core drill vs core bit

core drill and core bit both are nouns.

Word	Noun	Adjective	Verb	Adverb
core drill	Yes	No	No	No
core bit	Yes	No	No	No

core drill (noun)	core bit (noun)
a drill that removes a cylindrical core from the drill hole	a hollow drilling bit that is the cutting part of a core drill; allows core samples to be taken