A mari usque ad mare - From sea to sea
A posse ad esse - From possibility to actuality
A priori - From what comes before
A posteriori - From what comes after
Ab absurdo - From the absurd
Ab aeterno - From the beginning of time
Ab hinc - From here on
Ab imo pectore - From the bottom of the heart
Ab incunabulis - From the cradle
Ab initio - From the beginning
Ab origine - From the origin
Ab ovo - From the egg
Ad absurdum - To the point of absurdity
Ad astra per aspera - To the stars through difficulty
Ad augusta per angusta - To high places by narrow roads
Aut disce aut discede - Either learn or leave
Aut vincere aut mori - Either conquer or die
Auxilio ab alto - By help from on high
Anno mundi - In the year of the world
Annus mirabilis - Year of wonders
Ad captandum vulgus - To appeal to the crowd
Acta est fabula, plaudite! - The play is over, applaud!
Ab/Ex uno disce omnes - From one person, learn all people