noun
(derogatory) A jerk; a person who is unlikable, detestable, or contemptible because they are stupid, foolish, clumsy, oafish, inept, malicious, or unpleasant.
(derogatory) A deplorable, pitiful person.
verb
(slang, intransitive, rare) To behave like a schmuck.
(slang, transitive, rare) To mash or smoosh.