"stupid person," 1967, originally U.S. student slang, perhaps from earlier meaning "penis" (1964), itself probably an alteration of dick (n.). Related: Dorky; dorkiness.

Brazilian dance of African origin, 1885, Zemba, from Portuguese samba, shortened form of zambacueca, a type of dance, probably altered (by influence of zamacueco "stupid") from zambapalo, the name of a grotesque dance, itself an alteration of zampapalo "stupid man," from zamparse "to bump, crash." It was noted in 1938 as "just beginning to make its way in the New York nightclubs." As a verb from 1949.

"stupid person," 1809 (dom cop, in Washington Irving), from German dummkopf, literally "dumb head;" see dumb (adj.) + cup (n.).

"fool, stupid man," mid-15c., jobard, probably from French jobard (but this is not attested before 16c.), from jobe "silly." Earlier jobet (c. 1300).

"stupid person," by 1951, American English, from dumb (adj.). The Disney musical cartoon is from 1941; in it the elephant's name is a mocking nickname based on Jumbo.

also halfhearted, "showing little enthusiasm," early 15c.; see half + -hearted. Related: halfheartedly; halfheartedness. English in 17c. had also half-headed "stupid."