mull over vs cerebrate

mull over and cerebrate both are verbs.

Word	Noun	Adjective	Verb	Adverb
mull over	No	No	Yes	No
cerebrate	No	No	Yes	No

As verbs, cerebrate is a hypernym of mull over; that is, cerebrate is a word with a broader meaning than mull over:

mull over: reflect deeply on a subject
cerebrate: use or exercise the mind or one's power of reason in order to make inferences, decisions, or arrive at a solution or judgments

Other hypernyms of mull over include cogitate, think.

mull over (verb)	cerebrate (verb)
reflect deeply on a subject	use or exercise the mind or one's power of reason in order to make inferences, decisions, or arrive at a solution or judgments