Someone or something that is old in age. This phrase is commonly used to refer to people or things that are along in years.
Example: I’ve had this same stove in my kitchen for nearly a decade. I’ve cooked many meals with it and it’s been reliable for a long time. However, lately it’s been struggling to heat things as well as it once did. This is understandable considering how long in the tooth it is, but I’m now in the market to buy a new one.
In other words, the stove is old.
Origin Of ‘Long In The Tooth’
The phrase “long in the tooth” originates from horses, or more specifically, a horse’s teeth. How so? Because the older a horse gets, the longer their teeth become. So it is possible to give an approximation for how old a horse is simply by looking at their teeth.
Now, let’s talk about when this expression shows up in print. There’s a small snippet in an article printed in the Huron Daily Huronite newspaper from the year 1889 that uses this expression. It is used in reference to a horse. To give context for the following quote, someone was in the market to buy a horse, and while analyzing a possible candidate, he had doubts about the horse’s age, so he said:
“‘Open his mouth. What did you say his age was? I think he’s a little long in the tooth. Seven years did you say he was? I should call him 10 or 11 years old.'”
Today, this phrase is used to describe the age of people or things, not just horses.
Here are two examples. The first sentence will use the phrase, while the other one will use a synonym.
- This lawnmower is not as effective it used to be. I’ll have to buy a new one soon, because this one has gotten long in the tooth.
- The average lifespan for a domesticated cat is around 15 years. My cat has lived longer than that, so he’s along in years, but he’s still going strong.
Note: The origin of many common idioms cannot be said with a certainty. So what’s provided in cases where the origin is unknown are explanations that may be plausible to how a phrase originated, but not necessarily so. If no explanations are given, then there will typically be a quote of the expression from an old newspaper, poem, or book. Usually, these quotes are the oldest that I could find of the phrase in writing.