weeder vs weed remover

weeder and weed remover both are nouns.

Word	Noun	Adjective	Verb	Adverb
weeder	Yes	No	No	No
weed remover	Yes	No	No	No

As nouns, weed remover is a hyponym of weeder; that is, weed remover is a word with a more specific, narrower meaning than weeder:

weeder: a hand tool for removing weeds
weed remover: a weeder with steel claws that grab weeds by the root for clean removal.

Other hyponyms of weeder include weed puller.

weeder (noun)	weed remover (noun)
a hand tool for removing weeds	a weeder with steel claws that grab weeds by the root for clean removal.
a farmhand hired to remove weeds