Is there another common English word that exhibits such varied meanings as "boot?" Or one that has shown such continual transformation during my years on the planet?
Like much of my early vocabulary, "boot" entered my life through the medium of radio baseball . In my mind's ear, I can hear the voice of Red Barber announcing that "umpire Babe Pinelli has just given the boot to Leo Durocher." "Given the boot" does not make the claim that Durocher was presented with footwear; it means that he was kicked out of the game as if with a metaphorically-booted foot.
Nor was it only obstreperous managers who were "booted." "There's a two-hopper to third, but Cox boots it" -- meaning that he bobbled it, even though the ball never touched his foot. In baseball, curiously, you can boot a ball with your hand, which is, logically speaking, as nonsensical as gloving it with your foot.
As everyone knows, a boot primarily protects the area from the shin down to the toes. But there's a second common meaning to "boot": "something extra," as in the phrase "to boot." "He's a great pitcher -- and a good hitter to boot." The shoe-ish meaning comes through old French from a Germanic source; the profit or use or something-extra meaning derives from an unrelated OE (Old English) word; moreover, in latter stages of its development "boot" has also been influenced by its phonological neighbors booty, and, I suspect, butt.
In order to gain some historical perspective, let us consider the ways in which Shakespeare makes use of the word boot. "To boot" meaning "in addition" is employed frequently, as, for example, when Henry IV swears "by my scepter and my soul to boot," or when Macduff says to Malcolm that "I would not be the villain that thou think'st/ For the whole space that's in the tyrant's grasp/ And the rich east to boot." A less familiar use occurs in The Winter's Tale, when Hermione, accused of adultery, concedes that "it shall scarce boot me/ To say 'not guilty.'" Her "boot" means that it will not be to her advantage or profit to assert her innocence. This signification can shade over into gain or even into a coin itself, as for example when Camillo passes money to Autolycus, saying,"hold thee, there's some boot." Contemplating his gain, Autolycus muses, "What an exchange had this been without boot! What a boot is here with this exchange." Just as boot is gain, so bootless means without gain or helpless, as when Henry V explains that he will be powerless to restrain a rampage: "We may as bootless spend our vain command/ Upon the enraged soldiers in their spoil."
Shakespeare gets some punning mileage out of the multiple meanings of "boot." Glendower boasts that "[T]hree times hath Henry Bolingbroke made head/ Against my power; thrice from the banks of Wye/ And sandy-bottom'd Severn have I sent him/ Bootless home and weather-beaten back. "Bootless" means helpless; but sardonic Hotspur, never noted for an sophisticated sense of humor, cannot resist the obvious: "Home without boots. And in foul weather too."
So a boot can be a shoe, an advantage, an addition, a reward, a help. But look what's happened to the poor helpless word in more recent times. "Boot Hill" is a cowboy frontier cemetery. Across the waters, a "boot" is the trunk of an automobile. The infamous "Denver boot" is a wheel clamp that immobilizes a vehicle. In the army, a boot is a recruit or rookie: "boot camp."
But then, along came the computer, where one "boots" or restarts one's machine. This use, I'm told, originated with the phrase, to "pull oneself up by one's own bootstraps" -- i.e. perform a difficult task at one's own initiative, just as a computer starts itself. There's also the warmboot, which sounds little too much like the old torture device, the Spanish boot and which can also be called a softboot (but not by me).
In Shakespeare's day, boot was not always distinguished from "booty" as in the case of the Archbishop of Canterbury's famous bees, which "like soldiers, armed in their stings,/ Make boot upon the summer's velvet buds,/ Which pillage they with merry march bring home." Booty as pillage survives to this day, but is, I think, obsolescent. Nowadays, booty is more likely to be used in the phrase "booty call" which means (and here I'm relying on the invaluable Urban Dictionary) a "telephone call made to request a sexual encounter." Who would ever have devised or imagined such an innovation? Does this booty derive from "shake your booty," meaning to move your butt or bottom in a sexually suggestive way? Not a meaning known to Shakespeare, or at least, not one that the Shakespeare concordance acknowledges.
Other words of my life: slouch, cishet, yips, ramps, jot and tittle, worship, mucilage. spatchcock, umpire.