broadcast vs circulate

broadcast is a noun but circulate is not a noun.

Word	Noun	Adjective	Verb	Adverb
broadcast	Yes	No	Yes	No
circulate	No	No	Yes	No

As verbs, broadcast and circulate are synonyms defined as:

broadcast (noun)	circulate (noun)
message that is transmitted by radio or television
a radio or television show

broadcast (verb)	circulate (verb)
cause to become widely known	cause to become widely known
broadcast over the airwaves, as in radio or television	become widely known and passed on
sow over a wide area, especially by hand	move around freely from person to person or from place to place
	move through a space, circuit or system, returning to the starting point
	cause to be distributed
	cause to move in a circuit or system