Countersunk
Pronunciation : Coun"ter*sunk` (-snk`)
Part of Speech : p.
Definition : 1. Chamfered at the top; -- said of a hole.
2. Sunk into a chamfer; as, a countersunk bolt.
3. Beveled on the lower side, so as to fit a chamfered countersink; as, a countersunk nailhead.
p. & a. from Countersink.
Source : Webster's Unabridged Dictionary, 1913