If it's all Greek to you, you'd best move along. But if it's Latin, well, you've come to the right place. If you want to appear to be a smarty pants writer and drop an occasional Latin phrase, take you pick.

annus mirabilis - wonderful year

arbiter elegantiae - judge of the elegant; one who knows the good things in life

bona fides - good faith; credentials

carpe diem - sieze the day; enjoy the present

casus belli - cause justifying a war

caveat emptor - buyer beware

cui bono? - for whose advantage?

de facto - of fact; it is

de gustibus non est disputandum - no disputing tastes; there is no accounting for taste

Dei gratia - by the grace of God

Deo gratias - thanks to God

Deo volente - God willing

dis aliter visum - it seemed otherwise to the gods

Dominus vobiscum - Lord be with you

dulce et decorum est pro patria mori - sweet and seemly it is to die for one’s country

ecce homo - behold man

ex cathedra - with authority

ex more - with or according to customs

exempli gratia - for example (e.g.)

genius loci - spirit of the location

hic et ubique - here and everywhere

hinc illae lacrimae - hence, those tears

humanum est errare - to err is human; human is to err

id est - that is (i.e.)

in extremis - at death

in hoc signo vinces - by this sign, you conquer

in loco parentis - in place of the parent

in medias res - into the middle of things; the heart of the matter

in omnia paratus - prepared for all; ready for anything

in perpetuum - forever; perpetually

in propia persona - in person; in one’s own life or words

in statu quo - as things were

in toto - entirely; in total

ipso jure - the law itself

jure divino - Divine law

labor omnia vincit - labor conquers all things; effort results in victory

laborare est orare - to work is to pray

laus Deo - praise God

loco citato - in the location cited

loquitur - he speaks

mens sana in corpore sano - of sound mind in a healthy body

meum et tuum - mine and yours

modus operandi - mode of operating

morituri te salutamus - we who are about to die, salute you

motu proprio - of one’s own accord; on your own

multum in parvo - there is much in little

nemo me impune lacessit - no one attacks me with impunity

nil admirari - wondering at nothing

nolens volens - willing or not

Nota Bene - note well; pay special attention to

omnia vincit amor - love conquers all

opere citato - in the volume cited; in the book cited

otium cum dignitate - leisure with dignity

passim - here and there

pater patriae - father of his country

pax vobiscum - peace be with you

persona non grata - unwelcome person

primus inter pares - first among equals

pro bono publico - for the public good

pro Deo et ecclesia - for God and the Church

pro forma - as a matter of form; standard

quod erat demonstrandum - which was demonstrated; that which was shown

requiescat in pace - rest in peace

sic - thus; so it was

sic passim - so throughout

sic semper tyrannis - thus always to tyrants

sine die - some day; not a particular time

sine quo non - without which, nothing; it is essential

tempus fugit - time flies

timeo Danaos et dona ferentes - I fear the Greeks, even when they bear gifts

verbatim et literatim - word for word, letter for letter