"In a coon's age" is an American phrase meaning "in a very long time." In a coon's age is an Americanism recorded in 1843 and probably related to the old English expression 'in a crow's age,' meaning the same. The American term is an improvement, if only because the
raccoon was thought to live longer -- up to 4-5 years in the wild - than the crow. The expression may date from an earlier time in the 1800's when the exact age raccoons lived to was not known. They may live up to the same age as a dog in captivity.
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