Wiktionary
n. 1 (&lit The least age at which one is permitted by law to drink alcoholic beverages English) 2 (context poker slang English) A two and an ace as a starting hand in Texas hold 'em
WordNet
n. the age at which is legal for a person to buy alcoholic beverages
Usage examples of "drinking age".
A couple of teenagers, probably a year or two beneath the legal drinking age, had already come to the stairs looking for Jamesie to join them.
Zach was evidently so poleaxed by the concept of an enforced legal drinking age that his silver tongue had deserted him.
Although the drinking age in Pennsylvania is twenty-one, I must look easily that in my one good suit and Fazza's old black overcoat - in fact, I probably look like a freshly released young convict, tall and hungry and very likely not bolted together right.
The lobby was filling with people, but all of them were above drinking age.
A boy well under legal drinking age sat cross-legged on the floor, cradling a broken arm.