Chump

Noun

 * 1) 🇺🇸 the opposite of a champ; a loser
 * Don't be such a chump.
 * 1) the smaller of two bullies
 * I'll take on that chump, and you fight the other one.
 * 1)  an unintelligent person; a blockhead
 * That chump wouldn't know his ass from a hole in the ground.
 * 1) a gullible person; a sucker; someone easily taken advantage of; the target of a scam
 * It shouldn't be hard to put one over on that chump.
 * 1) someone lacking good sense - especially considered so for being scrupulous or unselfish
 * What a chump! He could have kept that money!
 * 1) the thick end (originally of a joint of meat)

Thesaurus
asshole, babe, bean, boob, booby, butt, champ, chaw, chew, chomp, cinch, conk, credulous person, crunch, cull, ding-a-ling, dingbat, dingdong, dolt, dolthead, dome, dupe, easy mark, easy pickings, fall guy, fathead, fish, fool, galoot, gobe-mouches, goof, greener, greenhorn, greeny, gudgeon, gull, head, headpiece, innocent, jerk, jerk-off, klutz, leadpipe cinch, mark, masticate, monkey, munch, mutt, noddle, noggin, noodle, oaf, patsy, pigeon, plaything, poll, prize sap, pushover, ruminate, sap, saphead, sawney, schlemiel, scrunch, sitting duck, stooge, sucker, toy, trusting soul, victim