# long in the tooth

idiom

Source: https://englishreference.com/idiom/long-in-the-tooth
Updated: 2026-08-10

## Meaning

Old; aged.

## Examples

- That old car is getting a bit long in the tooth.
- You look long in the tooth for a professional athlete.
- My computer is getting long in the tooth, so it takes forever to open simple files.
- Even though the manager is long in the tooth, his deep experience helps the company navigate difficult financial periods that younger staff might struggle with.
- Although the actor is becoming long in the tooth, he still delivers a powerful performance that captivates the entire audience.

## Origin

The idiom is likely a product of the equestrian trade, derived from the practice of estimating a horse’s age by the length and angle of its teeth. As a horse matures, its gums recede and its incisors appear longer and more rectangular, eventually meeting at a notably steep angle. This physiological shift provided a visual metric for buyers, though the story remains a probable rather than a definitive origin. A similar logic informs the advice not to look a gift horse in the mouth, suggesting that the dental health of a free animal is a matter of secondary importance. (disputed)

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.