M

Magister artis ingeniique largitor venter - Necessity is the mother of all invention
Magister Artium (MA) - Master of arts
Magister mundi sum! - I am the master of the universe!
Magna charta - Great paper
Magna cum laude - With great honour or academic distinction
Magna res est vocis et silentii temperamentum - The great thing is to know when to speak and when to keep quiet
Magnas inter oper inops - A pauper in the midst of wealth. (Horace)
Magnificat - It magnifies
Magnum bonum - A great good
Magnum opus - Great work, the major work of one's life
Maior risus, acrior ensis: quadragesima octava regula quaesitus - The bigger the smile, the sharper the knife: the 48th rule of acquisition
Mala fide - In bad faith (something which is done fraudulently)
Male parta male dilabuntur - What has been wrongly gained is wrongly lost. (Ill-gotten gains seldom prosper.) (Cicero)
Malum consilium quod mutari non potest - It's a bad plan that can't be changed. (Publilius Syrus)
Malum prohibitum - A prohibited wrong. A crime that society decides is wrong for some reason, not inherently evil
Malum quidem nullum esse sine aliquo bono - There is, to be sure, no evil without something good. (Pliny the Elder)
Manus in mano - Hand in hand
Manus manum lavat - One hand washes the other. The favor for the favor. (Petronius)
Mater artium necessitas - Necessity is the mother of invention
Mater dolorosa - Sorrowful mother. (Virgin Mary)
Mater memento mori - Remember your mortality
Mater tua criceta fuit, et pater tuo redoluit bacarum
Mater - Mother
Mater familias - Mother of family
Materia medica - Medical matter
Materiam superabat opus - The workmanship was better than the subject matter. (Ovid)
Maxima debetur puero reverentia - We owe the greatest respect to a child
Maximus in minimis - Great in little things
Me fallit - I do not know
Me iudice - I being judge; in my judgement
Me oportet propter praeceptum te nocere - I'm going to have to hurt you on principle
Mea maxima culpa - Through my very great fault
Mea mihi conscientia pluris est quam omnium sermo - My conscience means more to me than all speech. (Cicero)
Medice, cura te ipsum! - Physician, heal thyself! (Versio Vulgata)
Medici graviores morbos asperis remediis curant - Doctors cure the more serious diseases with harsh remedies. (Curtius Rufus)
Medicus curat, natura sanat - The physician treats, nature cures
Medio tutissimus ibis - You will go safest in the middle. (Moderation in all things) (Ovid)
Mei capilli sunt flagrantes - My hair is on fire
Meliora cogito - I strive for the best
Melius est praevenire quam praeveniri - Better to forestall than to be forestalled
Melius frangi quam flecti - It is better to break than to bend
Mellita, domi adsum - Honey, I'm home
Memento mori - Remember that you must die
Memento vivere - A reminder of life (literally remember that you have to live)
Memorabilia - Memorable things
Memorandum - A note of; a thing to be remembered
Memoria in aeterna - In everlasting remembrance
Memoriter - From memory
Mendacem memorem esse oportet - A liar needs a good memory. (Quintilianus)
Mens agitat molem - The mind moves the matter. (Vergil)
Mens rea - Guilty mind
Mens regnum bona possidet - An honest heart is a kingdom in itself. (Seneca)
Mens sana in corpore sano - A sound mind in a sound body. (Juvenalis)
Mens sibi conscia recti - A mind conscious of its rectitude
Meum cerebrum nocet - My brain hurts
Meum pactum dictum - My word is my bond
Mihi cura futuri - My concern is the future
Millennium (millennia) - A thousand year period
Minime senuisti! - You haven't aged a bit!
Minus habens - Absentminded
Mirabile dictu - Wonderful to say/relate. (Vergil)
Mirabile visu - Wonderful to behold
Miserere - Have mercy
Missa solemnis - Solemn Mass. (high Mass)
Mittimus - We send (to prison)
Modus agendi - Manner of operation
Modus operandi (m.o.) - Way of operating
Modus vivendi - Way of living
Morituri te salutant - Those who are about to die salute you
Mors ultima linea rerum est - Death is everything's final limit. (Horace)
Mors ultima ratio - Death is the final accounting
Mortvi non mordant - Dead men don't bite; Dead men tell no tale
Motu proprio - Of one's own initiative
Mulier taceat in ecclesia - Let the woman be silent in church. (Paul)
Multi famam, conscientiam pauci verentur - Many fear their reputation, few their conscience. (Pliny)
Multis post annis - Many years later
Multum in parvo - Much in little. (small but significant)
Multun, non multa - Much, not many (quality not quantity)
Mundus vult decipi, ergo decipiatur - The world wants to be deceived, so let it be deceived!
Mundus vult decipi - The world wants to be deceived
Munit haec et altera vincit - One defends and the other conquers
Mus uni non fidit antro - A mouse does not rely on just one hole. (Plautus)
Musica delenit bestiam feram - Music soothes the savage beast
Mutatis mutandis - The necessary changes having been made
Mvlti svnt vocati, pavci vero electi - Many are called [but] few are chosen