[tr?'pan]
¦ noun
1. chiefly historical a trephine (hole saw) used by surgeons for perforating the skull.
2. a borer for sinking shafts.
¦ verb (trepans, trepanning, trepanned) perforate (a person's skull) with a trepan.
Derivatives
trepanation ?tr?p?'ne??(?)n noun
Origin
ME: the noun via med. L. from Gk trupanon, from trupan 'to bore', from trupe 'hole'; the verb from OFr. trepaner.