Is it ensure, insure, or assure?
"to squat, crouch," 1720, Scottish, of uncertain origin, possibly from a Scandinavian source, cf. Old Norse huka "to crouch," hoka, hokra "to crawl." Hunker down, Southern U.S. dialectal phrase, popularized c.1965, from northern British hunker "haunch." Related: Hunkered; hunkering.