The words and phrases set out on this page are in common use and are worth knowing:

Ab initio
From the beginning


Ad hoc

For this special purpose  / improvised


Ad infinitem
Without limit


Ad lib
Improvisation


Ad nauseam
Repetitious argument or debate


Bona fide
With good faith (genuine)


Carpe diem
Seize the day


Caveat emptor
Let the buyer beware


Circa
Around, close too


Ergo
Therefore


Erratum
An error


Ex Gratia
Out of kindness


In situ
In its original situation


Nil desperandum
Do not despair


Per
Each


Per capita
For each person


Per se
For itself


Pro rata
In proportion


Per diem
Each day


Post mortem
After death



Quasi
As if, similar to


Status Quo
Give or take / Equivalent


Verbatim
The exact words


Via
By the way of


Vice versa
The other way round