spit out vs emit

spit out and emit both are verbs.

Word	Noun	Adjective	Verb	Adverb
spit out	No	No	Yes	No
emit	No	No	Yes	No

As verbs, emit is a hypernym of spit out; that is, emit is a word with a broader meaning than spit out:

Other hypernyms of spit out include let loose, let out, utter.

spit out (verb)	emit (verb)
spit up in an explosive manner	expel (gases or odors)
discharge (phlegm or sputum) from the lungs and out of the mouth	express audibly; utter sounds (not necessarily words)
utter with anger or contempt	give off, send forth, or discharge; as of light, heat, or radiation, vapor, etc.