ˌtrepəˈnāshən noun
( -s )
Etymology: Middle English trepanacioun, from Middle French trepanation, from trepan (from Medieval Latin trepanum ) + -ation
1. : the act or process of perforating a skull with a surgical instrument
2. : a hole in the skull produced surgically
hundreds of crania showing trepanations … have received close scrutiny by prehistorians — W.T.Corlett