He’ll give you the answer that you’ll … endorse?
Dear Word Detective: My local computer guru has labeled my three-year old computer “long in the tooth.” What is the source of this now seldom-used phrase? — Dick Stacy.
Oh boy. Three years old, eh? That’s a pretty good illustration of why “local computer guru” strikes me as one of the most ominous phrases in the English language, right up there with “Free Estimate” and “Your call is important to us.” A three-year old computer is not “long in the tooth” on my planet. I’m typing this on one that’s almost ten. But I may not a good judge of such things. I realized recently that I’ve been wearing the same belt every day for more than twenty years. Hey, it’s a nice belt. Well made, obviously.
“Long in the tooth” is, of course, a venerable English idiom meaning “showing its age,” “of advanced years,” or simply “old,” with strong implications of decrepitude. The earliest printed instance of the phrase found so far is from the 19th century, but it may be much older (“She was lean, and yellow, and long in the tooth; all the red and white in all the toyshops of London could not make a beauty of her,” WM Thackeray, 1852).
The source of “long in the tooth” was, fittingly, the primary mode of transport at that time, the humble horse. Fans of TV’s Greatest Sitcom Ever, Mister Ed, will remember that when Ed talked, his teeth were very prominent. (Some people say that Ed didn’t really talk, and in moving his mouth he was only trying to remove peanut butter that the TV crew had put there, but people who say that are joyless cynics.) The Wikipedia entry on Mister Ed is fascinating, by the way.
In any case, apparently it’s not all that easy to tell from just looking at a horse just how old the critter is. But when horses age, their gums recede, eventually to the point where the roots of Horsie’s teeth are visible, which makes the teeth themselves appear longer. Thus a horse visibly “long in the tooth” would be judged to be very mature at least, and possibly quite old. So a method of judging the age of a horse, originally of interest only to horse-traders and racing touts, gave us the common expression “long in the tooth,” meaning “over the hill.”
Judging a horse’s age by prying open its mouth and looking at its teeth does seem a rather obscure source for such a popular figure of speech as “long in the tooth,” but that was not the only common saying born of the practice. If you happened to be given a horse as a gift, it was considered very rude and ungrateful to immediately take a close look at its teeth to judge its age, especially in the presence of the gift-giver. Thus as long ago as the 16th century the proverb “Never look a gift horse in the mouth” served as a general warning never to criticize or find fault with a gift or an occasion of good fortune (“It is a madness … to look a gift Horse in the Mouth,” 1707). As a figure of speech meaning “to show ingratitude,” “to look a gift horse in the mouth” was followed about 200 years later by an equally vivid phrase, “to bite the hand that feeds you.” I’ve always wondered if that latter saying might have been inspired by a resentful horse who was tired of having his mouth pried open.