saturate vs fill up

saturate and fill up both are verbs.

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

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

Other hypernyms of saturate include fill, make full.

saturate (verb)	fill up (verb)
cause (a chemical compound, vapour, solution, magnetic material) to unite with the greatest possible amount of another substance	make full, also in a metaphorical sense
infuse or fill completely	become full
	eat until one is sated
	fill or stop up