An archaic or dialect term for a polecat, a small carnivorous mammal with a distinctive musky smell.
From Old English 'ful' (foul) + 'mearth' (marten, a type of animal), literally meaning 'foul marten.' The polecat was named for its notoriously bad odor, and this compound word evolved in Middle English.
Polecats got their 'foul' reputation from their musk glands, which they use for marking territory and defense—it's so pungent that the animal earned a name literally meaning 'stinking marten' in multiple European languages.
Complete word intelligence in one call. Free tier — 50 lookups/day.