think over vs excogitate

think over and excogitate both are verbs.

Word	Noun	Adjective	Verb	Adverb
think over	No	No	Yes	No
excogitate	No	No	Yes	No

As verbs, think over and excogitate are synonyms defined as:

Other synonyms of think over include chew over, contemplate, meditate, mull, mull over, muse, ponder, reflect, ruminate, speculate.

think over (verb)	excogitate (verb)
reflect deeply on a subject	reflect deeply on a subject
	come up with (an idea, plan, explanation, theory, or principle) after a mental effort