invent vs excogitate

invent and excogitate both are verbs.

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

As verbs, invent and excogitate are synonyms defined as:

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

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

invent (verb)	excogitate (verb)
come up with (an idea, plan, explanation, theory, or principle) after a mental effort	reflect deeply on a subject
concoct something artificial or untrue	come up with (an idea, plan, explanation, theory, or principle) after a mental effort