"Cogito, ergo sum" and other useful Latin words, phrases and sayings, with their meanings.
a cappella - in church (vocal music only)
ad hoc - for a particular purpose (only)
ad infinitum - to infinity (without end)
ad nauseum - to a sickening degree
alma mater - fostering mother (a school or university you attended or from which you graduated)
a mari usque ad mare - from sea to sea (motto of Canada)
annus horribilis - a horrible year
ante - before
antebellum - before the war
a posteriori - from the latter
a priori - from the former
arcana - secrets (mysterious knowledge known only to initiates)
ars gratia artis - art for art's sake
ave atque vale - hail and farewell
beatae memoriae - of blessed memory
bene - good
bis in die - twice a day
bona fide - (adjective) in good faith, well-intentioned, fairly
bona fides - (noun) honest intention
bona fortuna - good luck!
bovina sancta - holy cow!
carpe diem - seize the day
caveat emptor - let the buyer beware (i.e. - take the risk)
cave canem - beware of the dog
cogito, ergo sum - I think, therefore I am
commune bonum - the common good
corpus christi - the body of Christ
crux - puzzle
cum laude - with praise
de facto - something that is automatically accepted
de novo - anew
Dei Gratia - by the grace of God
Deus vobiscum - God be with you
dramatis personae - characters of the play
ecce homo - behold the man
emeritus - honorary, by merit
eo ipso - by that very act
e pluribus unum - out of many, one
ergo - therefore
errata - a list of errors
et cetera - and the rest (etcetera, etc.)
ex cathedra - from the chair (of authority)
ex libris - from the library (of)
ex tempore - off the cuff, without preparation
fiat lux - let there be light
finis - the end
habeas corpus - you must have the body (you must justify an imprisonment)
hic et nunc - here and now
in absentia - in one's absence
in extremis - in extreme circumstances (e.g. - at point of death)
in loco parentis - in the place of a parent
in perpetuum - forever
in toto - totally, entirely
modus operandi - a way of operating
omnia vincit amor - love conquers all
post mortem - after death
post partum - after childbirth
pro bono publico - for the public good
quater in die (Q.I.D.) - take 4 times a day
qui bono? - who benefits?
quid pro quo - something for something
quo vadis? - where are you going?
regina - queen
rex - king
rigor mortis - the rigidity of death
tabula rasa - a clean slate
tempus fugit - time flees (more common: time flies)
terra firma - solid ground