Tre·pan, v. t. & i. [imp. & p. p. Trepanned p. pr. & vb. n. Trepanning.] Surg. 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.
trepan
n 1: a surgical instrument used to remove sections of bone from
the skull [syn: trephine]
2: a drill for cutting circular holes around a center
v : cut a hole with a trepan, as in surgery
[also: trepanning, trepanned]