instill vs fill up

instill and fill up both are verbs.

Word	Noun	Adjective	Verb	Adverb
instill	No	No	Yes	No
fill up	No	No	Yes	No

As verbs, fill up is a hypernym of instill; that is, fill up is a word with a broader meaning than instill:

Other hypernyms of instill include fill, make full.

instill (verb)	fill up (verb)
fill, as with a certain quality	make full, also in a metaphorical sense
produce or try to produce a vivid impression of	become full
teach and impress by frequent repetitions or admonitions	eat until one is sated
enter drop by drop	fill or stop up
impart gradually