Trephines

Part of speech: noun, verb

Definitions

1. Cuts a round section out of a bone, especially the skull, with a hollow surgical saw ; a hollow circular saw used by surgeons to cut such discs of bone
2. Removes a circular piece of bone, typically from the skull, using a special cutting tool ; a hollow surgical saw designed to cut out round sections of bone
3. Saws a round plug of bone out of the skull during surgery ; the hollow cylindrical instrument surgeons use to cut round bone discs

Etymology: "Trephines" is the plural of "trephine," a noun for a surgical instrument, and also a verb form meaning to operate on the skull with such an instrument. The original sense is a tool for boring, not a medical one: the Ancient Greek "trúpanon" meant "auger" or "borer," a carpenter's drill. The Romans took the word over as "trepanum," and it passed into French as "tréphine," the name of a small saw used to cut a circular section out of bone. The word's near relative is "trepan," which came into English through a different path and was used for the same kind of bone-cutting operation. The two are doublets: separate borrowings of one Greek original that reached English by different routes and took on slightly different senses. Both trace back to the same drilling image, so a surgeon cutting into a skull is, etymologically, still boring a hole.

Synonyms: trephan, trepan