Weasel-like mammal (7)
(Other definitions for polecat that I've seen before include "Weasel-like creature" , "Malodorous carnivore" , "American skunk" , "Weasel-like mammal" , "weaselly creature" .)
(Other definitions for stoat that I've seen before include "Member of the weasel family" , "Small carnivore" , "furry animal" , "Short-tail weasel" , "Small carnivorous mammal of the weasel family" .)