n.
Pronunciation: tri- ' pan
Function: transitive verb
Inflected Form: tre · panned ; tre · pan · ning
Etymology: Middle English, from trepane trephine
Date: 15th century
1 : to use a trephine on (the skull)
2 : to remove a disk or cylindrical core (as from metal for testing)
– trep · a · na · tion \ ˌ tre-p ə - ' n ā -sh ə n \ noun