dewclaw
noun
dew·claw ˈdü-ˌklȯ 
also ˈdyü-
: a vestigial digit not reaching to the ground on the foot of a mammal
also : a claw or hoof terminating such a digit see cow illustration
Example Sentences
Recent Examples on the Web Long nails can catch on upholstery and tear the dewclaw partly off the leg. 
Kim Campbell Thornton, Star Tribune, 19 Mar. 2021
Kim Campbell Thornton, Star Tribune, 19 Mar. 2021 Word History
First Known Use
1576, in the meaning defined above
Medical Definition
dewclaw
noun
dew·claw ˈd(y)ü-ˌklȯ
: a vestigial digit not reaching to the ground on the foot of a mammal
also : a claw or hoof terminating such a digit