1. trepan - Noun
2. trepan - Verb
A crown-saw or cylindrical saw for perforating the skull, turned, when used, like a bit or gimlet. See Trephine.
A kind of broad chisel for sinking shafts.
To perforate (the skull) with a trepan, so as to remove a portion of the bone, and thus relieve the brain from pressure or irritation; to perform an operation with the trepan.
A snare; a trapan.
a deceiver; a cheat.
To insnare; to trap; to trapan.
Source: Webster's dictionary