noun
A child who is thirteen years old.
(dated) A member of the 13th Gen; a Generation Xer or Gen-Xer.
(card games, especially bridge) The last playing card of a suit left after the other twelve have been played.
(cricket) A hit for thirteen runs.
(numismatics, dated) A coin worth thirteenpence, especially an Irish shilling (as contrasted with a British shilling which was worth twelvepence).
(poetry) A thirteen-syllable line or series of lines in a poem.
(US, climbing) A mountain rising to more than 13,000 feet (about 4,000 metres) but less than 14,000 feet above mean sea level.