monger vs barrow-boy

monger and barrow-boy both are nouns.

Word	Noun	Adjective	Verb	Adverb
monger	Yes	No	Yes	No
barrow-boy	Yes	No	No	No

As nouns, barrow-boy is a hyponym of monger; that is, barrow-boy is a word with a more specific, narrower meaning than monger:

monger: someone who purchases and maintains an inventory of goods to be sold
barrow-boy: a hawker of fruit and vegetables from a barrow

monger (noun)	barrow-boy (noun)
someone who purchases and maintains an inventory of goods to be sold	a hawker of fruit and vegetables from a barrow

monger (verb)	barrow-boy (verb)
sell or offer for sale from place to place