Legal Maxim
Maximus magister erroris populus est - The people are the greatest master of error.
Melior est conditio possidentis, ubi neuter jus habet - Better is the condition of the possessor where neither of the two has the right.
Melior testatoris in testamentis spectanda est - In wills the intention of a testator is to be regarded.
Meliorem conditionem suam facere potest minor deteriorem nequaquam - A minor can make his position better, never worse.
Mens rea - Guilty state of mind.
Mentiri est contra mentem ire - To lie is to act against the mind.
Merito beneficium legis amittit, qui legem ipsam subvertere intendit - He justly loses the benefit of the law who seeks to infringe the law.
Minatur innocentibus qui parcit nocentibus - He threatens the innocent who spares the guilty.
Misera est servitus, ubi jus est vagum aut incertum - It is a miserable slavery where the law is vague or uncertain
Source: Inrebus.com.