precum noun 1verb 1forms 4 noun1 •(slang, vulgar) Cowper's fluid; pre-ejaculate.The shaft was fat, long and already half-hard. Ulrich didn't mean to pry, but he understood (as precum slicked his palm) that this was a man who liked to play for hours before he came. — 1996 verb1 •(slang, vulgar) To release Cowper's fluid (pre-ejaculate). formsprecummed · precame · precumming · precums