drinking age
nounEtymology In most of the United States, the drinking age is 21 years. In poker, an ace often has the value of one. Hence, one could say that a 2-A hand in poker could have a value equivalent to 2-1.
1
Used other than figuratively or idiomatically: The least age at which one is permitted by law to drink alcoholic beverages.
2
Card games, Poker Slang A two and an ace as a starting hand in Texas hold 'em