footwear, early 14c., from Old French bote "boot" (12c.), with corresponding words in Provençal and Spanish, of unknown origin, perhaps from a Germanic source. Originally for riding boots only. An old Dorsetshire word for "half-boots" was skilty-boots [Halliwell, Wright].
"profit, use," Old English bot "help, relief, advantage; atonement," literally "a making better," from Proto-Germanic *boto (see better (adj.)). Cf. German Buße "penance, atonement," Gothic botha "advantage." Now mostly in phrase to boot (Old English to bote).
"to kick," 1877, American English, from boot (n.1). Generalized sense of "eject, kick out" is from 1880. Related: Booted; booting.
"start up a computer," 1975, from bootstrap (v.), a 1958 derived verb from bootstrap (n.) in the computer sense.
(Variations: ass or sweet ass or bibby or bippy or bottom dollar or buns or left nut or life or shirt or whiskers may replace boots)Tobe absolutely assured; count on it: You can bet your boots I'll be there/ You bet your sweet ass it was easier at the museum/ I'll bet my left nut that's what was happening (entry form 1800s+, variants fr then until mid1900s+)