1703, "short, thick lump of wood," akin to Old Norse kumba "block of wood." Meaning "blockhead" is first attested 1883. Chump change attested by 1950.
: The honest, hardworking immigrant was a chump game
A stupid person, esp a dupe; sucker: I look like a chump these days (1877+)
: You were chumped, Donna Rice and Marla Trump (1920s+)
[origin unknown; perhaps an alteration of chunk referring to blockheadedness]