"lacking boots," late 14c., from boot (n.1) + -less.
bootless (adj.2)
"without advantage, unprofitable," late Old English botleas "unpardonable, not to be atoned for, without help or remedy," from boot (n.2) + -less. Meaning "useless, unprofitable" is from early 15c.
Bootes
booth
bootleg
bootlegger
bootlegging
bootless
boot-licker
bootstrap
booty
bootylicious
boo-ya