forty

Etymology

From Middle English fourti, feortiȝ, from Old English fēowertiġ, ultimately from Proto-Germanic *fedwōr tigiwiz (“forty”).

num

1. The cardinal number occurring after thirty-nine and before forty-one.
   'Tis forty years this very day, Since you and I, old girl, were married. 1825, unknown, Harrison's Amusing Picture and Poetry Book, page 35

noun

1. (slang) A bottle of beer containing forty fluid ounces.