1. Ab Initio
From the beginning.

2. Actionable per se 
The very act is punishable and no proof of damage is required.

3. Actio personalis moritur cum persona
A personal right of action dies with the person. In other sense, if he dies the right to sue is gone.

4. Actori incumbit onus probandi
The burden of proof is on the plaintiff.

5. Actus Non Facit Reum Nisi Mens Sit Rea
An act does not make anyone guilty unless there is criminal intent or a guilty mind.

6. Ad hoc
For this purpose only.

7. Alibi
At another place, elsewhere.

8. Amicus Curiae
A friend of court or member of the Bar who is appointed to assist the Court.

9. Ante Litem Motam
Before suit brought; before controversy instituted OR spoken before a lawsuit is brought.

10. Assentio mentium
The meeting of minds, i.e mutual assents.

11. Audi alteram partem
Hear the other side or no man shall be condemned unheard.

12. Bona fide
In good faith.

13. Bona vacantia
Goods without an owner.

14. Boni judicis est ampliare jurisdictionem
It is the part of a good judge to enlarge his jurisdiction, i.e. remedial authority or broad justice is good justice.

15. Caveat 
A caution registered with the public court to indicate to the officials that they are not to act in the matter mentioned in the caveat without first giving notice to the caveator.

16. Caveat actor
Let the doer beware.

17. Caveat emptor
Let the buyer beware.

18. Caveat venditor
Let the seller beware.

19. Certiorari
A writ by which orders passed by an inferior court is quashed.

20. Corpus
Body.

21. Corpus delicti
The facts and circumstances constituting a crime and Concrete evidence of a crime, such as a corpse (dead body).
Also,
It refers to the principle that ‘a crime must be proved to have occurred before a person can be convicted of committing that crime.’ (This definition is mostly used in Western Law.)

22. Damnum sine injuria
Damage without injury.

23. De facto
In fact.

24. De jure
By law.

25. De minimi
About minimal things.

26. De Minimis Non Curat Lex
The law does not govern trifles (unimportant things) or law ignores insignificant details.
or
A common law principle whereby judges will not sit in judgment of extremely minor transgressions (offence, wrongdoings) of the law.

27. De novo
To make something anew.

28. Dictum 
Statement of law made by judge in the course of the decision but not necessary to the decision itself.

29. Doli incapax  
Incapable of crime.

30. Detinue
Tort of wrongfully holding goods which belong to someone else.

31. Donatio mortis causa  
Gift because of death. (or a future gift given in expectation of the donor’s imminent death and only delivered upon the donor’s death.)

32. Estoppel 
Prevented from denying.

33. Ex gratia
As favour.

34. Ex officio  
Because of an office held.

35. Ex parte 
Proceedings in the absence of the other party.

36. Ex post facto 
Out of the aftermath. or After the fact.

37. Fatum
Beyond human foresight.

38. Factum probans  
Relevant fact.

39. Fraus est celare fraudem  
It is a fraud to conceal a fraud.

40. Functus officio 
No longer having power or jurisdiction.

41. Furiosi nulla voluntas est  
Mentally impaired or mentally incapable persons cannot validly sign a will, contract or form the frame of mind necessary to commit a crime. or a person with mental illness has no free will.

42. Habeas corpus 
A writ to have the body of a person to be brought in before the judge.

43. Ignorantia juris non excusat 
Ignorance of the law excuses not or Ignorance of the law excuses no one.
In other words,
A person who is unaware of a law may not escape liability for violating that law merely because one was unaware of its content.

44. Injuria sine damno  
Injury without damage.

45. Ipso facto 
By the mere fact.

46. In promptu  
In readiness.

47. In lieu of 
Instead of.

48. In personam  
A proceeding in which relief I sought against a specific person.

49. Innuendo 
Spoken words which are defamatory because they have a double meaning.

50. In status quo  
In the present state.

51. Inter alia 
Among other things.

52. Inter vivos 
(especially of a gift as opposed to a legacy) between living people.

53. Interest Reipublicae Ut Sit Finis Litium  
It means it is in the interest of the state that there should be an end to litigation.

54. Jus cogens (or ius cogens)
Compelling law.

55. Jus in personam 
Right against a specific person.

56. Jus in rem 
Right against the world at large.

57. Jus naturale 
Natural law.
Or in other words,
A system of law based on fundamental ideas of right and wrong that is Natural Law.

58. Jus non scriptum 
Customary law.

59. Jus scriptum 
Written law.

60. Jus 
Law or right.

61. Justitia nemini neganda est 
Justice is to be denied to nobody.

62. Lex non a rege est violanda 
The law must not be violated even by the king.

63. Locus standi 
Right of a party to an action to appear and be heard by the court and be heard by the court.

64. Mala fide 
In bad faith.

65. Malum in se or Mala in se (plural)
Wrong or evil in itself.

66. Malum prohibitum 
Crimes are criminal not because they are inherently bad, but because the act is prohibited by the law of the state.

67. Mandamus 
‘We command’. A writ of command issued by a Higher Court to Government/Public Authority, to compel the performance of a public duty.

68. Mens rea 
Guilty mind.

69. Misnomer 
A wrong or inaccurate name or term.

70. Modus operandi 
Way of working.

71. Modus Vivendi 
Way of living.

72. Mutatis Mutandis 
With the necessary changes having been made OR with the respective differences having been considered.

73. Nemo bis punitur pro eodem delicto 
Nobody can be twice punished for the same offence.

74. Nemo debet bis vexari pro una et eadem causa
It means no man shall be punished twice for the same offence.

75. Nemo debet esse judex in propria causa or Nemo judex in causa sua or Nemo judex in sua causa 
Nobody can be judge in his own case.

76. Nemo moriturus praesumitur mentire 
A man will not meet his maker (God) with a lie in his mouth or in other words ‘No man at the point of death is presumed to lie.’ 

77. Nemo Potest esse tenens et dominus 
Nobody can be both a landlord and a tenant of the same property.

78. Nolle prosequi
A formal notice of abandonment by a plaintiff or prosecutor of all or part of a suit.

79. Novation 
Transaction in which a new contact is agreed by all parties to replace an existing contract.

80. Nunc pro tunc 
Now for then. A ruling nunc pro tunc applies retroactively to correct an earlier ruling.

81. Non Sequitur 
A statement (such as a response) that does not follow logically from or is not clearly related to anything previously said.

82. Obiter dictum 
Things said by the way. It is generally used in law to refer to an opinion or non-necessary remark made by a judge. It does not act as a precedent.
In other words,
Obiter dictum means “that which is said in passing,” an incidental statement.

83. Onus probandi  
Burden of proof.

84. Pacta Sunt Servanda  
Agreements must be kept. or Agreements are legally binding.

85. Pari passu 
With an equal step. Read more about it on Wikipedia.

86. Particeps criminis 
A participator in the actual crime/partner in crime.

87. Per curiam (decision or opinion)
By the court.
In other words,
The decision is made by the court (or at least, a majority of the court) acting collectively.

88. Per se 
By itself.

89. Persona non grata 
A person who is unacceptable or unwelcome.
Opposite of persona non grata is persona grata.

90. Prima facie
At first sight.

91. Alimony 
A husband’s (or wife’s) provision for a spouse after separation or divorce; maintenance.
Palimony 
Money which a man pays to a woman with whom he has been living and from whom he is separated. Palimony has slightly different meanings in different jurisdictions.

92. Per curiam 
By a court.

93. Per incuriam 
Because of lack of care.

94. Prima facie 
On the face of it.

95. Quantum meruit 
What one has earned. or the amount he deserves.

96. Qui facit per alium, facit per se 
He who acts through another acts himself.

97. Quid pro quo 
Something for something.

98. Qui sentit commodum, sentire debet et onus 
It means he who receives advantage must also bear the burden.

99. Quo warranto 
By what authority. A writ calling upon one to show under what authority he holds or claims a public office.

100. Ratio decidendi 
Principle or reason underlying a court judgement. or The rule of law on which a judicial decision is based.

101. Respondeat superior 
Let the master answer.

102. Res ipsa loquitor 
The thing speaks for itself.

103. Res Judicata 
A matter already judged.

104. Res Judicata Pro Veritate Accipitur 
It means that a judicial decision must be accepted as correct.

105. Rex non protest peccare 
The king can do no wrong.

106. Salus populi est suprema lex 
The welfare of the is the supreme law.

107. Status quo 
State of things as they are now.

108. Sine die 
With no day (indefinitely).

109. Sine qua non 
“without which nothing”. An essential condition; a thing that is absolutely necessary. Basically a component of an argument that, if debunked, causes the entire argument to crumble.

110. Suo Motu
On its own motion.

111. Uberrima fides (sometimes uberrimae fidei) 
Utmost good faith.

112. Ubi jus ibi remedium 
Where there is a right, there is a remedy.

113. Veto 
Ban or order not to allow something to become law, even if it has been passed by a parliament.

114. Vice versa 
Reverse position.

115. Vis major 
Act of God.

116. Volenti non fit injuria 
Damage suffered by consent gives no cause of action.
or in other words,
If someone willingly places himself in a position where he knows that harm might result, then he is not able (allowed) to bring a claim against the other party in tort or delict (a violation of the law).

117. Vox populi 
Voice of the people or The opinion of the majority of the people.

118. Waiver 
Voluntarily giving up or removing the conditions.