A small toe or claw on the inner side of the hind leg of certain animals like dogs, cats, and deer, located above the main foot; it doesn't touch the ground when the animal walks.
From Old English dēaw (dew) + claw. Named because it hangs loosely and brushes through dew-covered grass as the animal walks. The term dates back at least to Middle English.
The 'dew' in dewclaw isn't about moisture—it's poetic observation: medieval people noticed these useless little claws brushing through dewy grass, so they named it that way.
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