dealer vs seedman

dealer and seedman both are nouns.

Word	Noun	Adjective	Verb	Adverb
dealer	Yes	No	No	No
seedman	Yes	No	No	No

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

dealer: someone who purchases and maintains an inventory of goods to be sold
seedman: a dealer in seeds

dealer (noun)	seedman (noun)
a firm engaged in trading	a dealer in seeds
a seller of illicit goods
the person who distributes the playing cards in a card game
someone who purchases and maintains an inventory of goods to be sold
the major party to a financial transaction at a stock exchange; buys and sells for his own account