trepan vs surgical operation

trepan and surgical operation both are nouns.

Word	Noun	Adjective	Verb	Adverb
trepan	Yes	No	Yes	No
surgical operation	Yes	No	No	No

trepan (noun)	surgical operation (noun)
a drill for cutting circular holes around a center	a medical procedure involving an incision with instruments; performed to repair damage or arrest disease in a living body
a surgical instrument used to remove sections of bone from the skull

trepan (verb)	surgical operation (verb)
cut a hole with a trepan, as in surgery