- a variety of mule deer, Odocoileus hemionus columbianus, of the western slope of the Rocky Mountains, having a tail that is black above.
Also blacktail deer [blak-teyl] /ˈblækˌteɪl/.
Origin of black-tailed deer
An Americanism dating back to 1800–10
Also called black·tail.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018