drill vs drill in

drill is a noun but drill in is not a noun.

Word	Noun	Adjective	Verb	Adverb
drill	Yes	No	Yes	No
drill in	No	No	Yes	No

As verbs, drill in is a hyponym of drill; that is, drill in is a word with a more specific, narrower meaning than drill:

Other hyponyms of drill include beat in, hammer in, ram down, inculcate, infuse, instill.

drill (noun)	drill in (noun)
systematic training by multiple repetitions
(military) the training of soldiers to march (as in ceremonial parades) or to perform the manual of arms
similar to the mandrill but smaller and less brightly colored
a tool with a sharp point and cutting edges for making holes in hard materials (usually rotating rapidly or by repeated blows)

drill (verb)	drill in (verb)
learn by repetition	teach by drills and repetition
teach by repetition
train in the military, e.g., in the use of weapons
undergo military training or do military exercises
make a hole, especially with a pointed power or hand tool