One who scoffs. Const. at; also (now rarely) of. Often spec., one who scoffs at religion or morality.

One who taunts: see the verb.

One who jeers or calls out in derision; a mocker, scoffer.

One who gibes; one who utters gibes and taunts.

One who sneers or cavils.

One who fleers; a mocker, †a ‘fawner’ (Johnson).

one who barracks.

U.S. slang (chiefly in African-American usage). A person who boasts, brags, or makes insulting remarks, esp. as part of a verbal contest.