barker vs promoter

barker and promoter both are nouns.

Word	Noun	Adjective	Verb	Adverb
barker	Yes	No	No	No
promoter	Yes	No	No	No

As nouns, promoter is a hypernym of barker; that is, promoter is a word with a broader meaning than barker:

barker: someone who stands in front of a show (as at a carnival) and gives a loud colorful sales talk to potential customers
promoter: someone who is an active supporter and advocate

Other hypernyms of barker include booster, plugger.

barker (noun)	promoter (noun)
informal terms for dogs	someone who is an active supporter and advocate
someone who stands in front of a show (as at a carnival) and gives a loud colorful sales talk to potential customers	a sponsor who books and stages public entertainments