booker vs showman

booker and showman both are nouns.

Word	Noun	Adjective	Verb	Adverb
booker	Yes	No	No	No
showman	Yes	No	No	No

As nouns, showman is a hyponym of booker; that is, showman is a word with a more specific, narrower meaning than booker:

Other hyponyms of booker include impresario, promoter.

booker (noun)	showman (noun)
someone who engages a person or company for performances	a sponsor who books and stages public entertainments
	a person skilled at making effective presentations