formulate vs excogitate

formulate and excogitate both are verbs.

Word	Noun	Adjective	Verb	Adverb
formulate	No	No	Yes	No
excogitate	No	No	Yes	No

As verbs, formulate and excogitate are synonyms defined as:

formulate and excogitate: come up with (an idea, plan, explanation, theory, or principle) after a mental effort

Other synonyms of formulate include contrive, devise, forge, invent.

formulate (verb)	excogitate (verb)
put into words or an expression	reflect deeply on a subject
elaborate, as of theories and hypotheses	come up with (an idea, plan, explanation, theory, or principle) after a mental effort
come up with (an idea, plan, explanation, theory, or principle) after a mental effort
prepare according to a formula