tusk

Tusk comes from Middle English tusk, from Old English tūsc or tūx, meaning 'canine tooth, tusk, molar.' That in turn traces back through Proto-West Germanic *tunsk to Proto-Germanic *tunþskaz, an extended form of *tanþs, 'tooth,' ultimately from Proto-Indo-European *h₃dónts, also meaning 'tooth.'

The word began as a general term for a canine or molar tooth in Old English, and over time narrowed to describe the specific, oversized teeth of animals like elephants and walruses.

Tusk is a doublet of tush, and it's a distant cousin of tooth itself, since both spring from the same Proto-Indo-European root for 'tooth.' It also shares roots with West Frisian tosk and Gothic tunþus, which both simply mean 'tooth.'