incubate vs brood

incubate is not a noun while brood is a noun.

Word	Noun	Adjective	Verb	Adverb
incubate	No	No	Yes	No
brood	Yes	No	Yes	No

As verbs, incubate and brood are synonyms defined as:

Other synonyms of incubate include cover, hatch.

incubate (noun)	brood (noun)
	the young of an animal cared for at one time

incubate (verb)	brood (verb)
sit on (eggs)	sit on (eggs)
grow under conditions that promote development	think moodily or anxiously about something
	be in a huff; be silent or sullen
	be in a huff and display one's displeasure
	hang over, as of something threatening, dark, or menacing