arrector pili muscle

noun

arrector pi·​li muscle -ˈpī-ˌlī-  -ˈpil-ē- 

: one of the small fan-shaped smooth muscles associated with the base of each hair that contract when the body surface is chilled and erect the hairs, compress an oil gland above each muscle, and produce the appearance of goose bumps

called also erector pili muscle, pilomotor muscle