AUC

Etymology 1
From,  or , both in reference to Rome's legendary establishment by Romulus. The era was not in common use by the Romans, who preferred dating by the years' consuls, but Roman historians give several dates for this era. The one most commonly used in the present day is Varro's, which dates from the third year of the sixth Olympiad (753BC).

Adverb

 * 1)  According to the Roman era, which reckons the number of years passed from the foundation of the city of Rome by Romulus, now usually taken as 753BC.

Etymology 2
English initialisms.

Noun

 * 1)  the area under the curve in a plot of concentration of drug in blood plasma against time.

Etymology 3
Initialism of Spanish Autodefensas Unidas de Colombia.

Proper noun

 * , a paramilitary group active from 1997 to 2006.

Etymology 4
Initialism.

Adverb

 * 1)   or : according to the Roman era, reckoning the years passed from the foundation of the city of Rome by Romulus, on April 21 in the various years 753BC, 752BC , 751BC , 750BC , or 747BC.