The Collaborative International Dictionary
Trephining
Trephine \Tre*phine"\, v. t. [imp. & p. p. Trephined; p. pr. & vb. n. Trephining.] To perforate with a trephine; to trepan.
Wiktionary
trephining
vb. (present participle of trephine English)
Usage examples of "trephining".
It wasn't just a simple trephining job that had been done on this increasingly mysterious liar.
I thought what would happen to his poor head, with the mark of trephining all the way around it, if I were to put the skull under the press and start applying it.