shout vs shout out

shout is a noun but shout out is not a noun.

Word	Noun	Adjective	Verb	Adverb
shout	Yes	No	Yes	No
shout out	No	No	Yes	No

As verbs, shout and shout out are synonyms defined as:

Other synonyms of shout include call, cry, holler, hollo, scream, squall, yell.

shout (noun)	shout out (noun)
a loud utterance; often in protest or opposition

shout (verb)	shout out (verb)
utter in a loud voice; talk in a loud voice (usually denoting characteristic manner of speaking)	utter a sudden loud cry
utter a sudden loud cry	utter in a very loud voice
utter aloud; often with surprise, horror, or joy
use foul or abusive language towards