Getting on in years, old, as in Aunt Aggie's a little long in the tooth to be helping us move. This expression alludes to a horse's gums receding with age and making the teeth appear longer. [Mid-1800s]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
How to use long in the tooth in a sentence
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