nail-biting adjective 1nail biting noun 1forms 2 adjective1 •That causes nervous anticipation or suspense.He said recent nail-biting finals had renewed interest in the end-of-season contests, after a series of one-sided beltings earlier this decade. — 2009 nail biting noun1 •The habit of biting one's fingernails. formsmore nail-biting · most nail-biting