botanist vs pomologist

botanist and pomologist both are nouns.

Word	Noun	Adjective	Verb	Adverb
botanist	Yes	No	No	No
pomologist	Yes	No	No	No

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

botanist: a biologist specializing in the study of plants
pomologist: someone versed in pomology or someone who cultivates fruit trees

Other hyponyms of botanist include mycologist, propagator.

botanist (noun)	pomologist (noun)
a biologist specializing in the study of plants	someone versed in pomology or someone who cultivates fruit trees