yo-yo

(yō′yō′)

☆

noun pl. yo-yos

a spool-like toy attached to one end of a string upon which it may be made to spin up and down
Slang a person regarded as stupid, ineffectual, inept, eccentric, etc.

Origin: < ?: the toy came to the U.S. from the Philippines

adjective

Informal up-and-down; fluctuating; variable

intransitive verb yo-yoed, yo-yoing

Informal to move up and down; fluctuate; vary

See yo-yo in American Heritage Dictionary 4

noun pl. yo-yos yo-yos

A toy consisting of a flattened spool wound with string that is spun down from and reeled up to the hand by motions of the wrist.
Informal One that undergoes frequent abrupt shifts or reversals, as of opinion or emotion; a vacillator.
Slang A stupid or objectionable person.