earthworm vs red worm

earthworm and red worm both are nouns.

Word	Noun	Adjective	Verb	Adverb
earthworm	Yes	No	No	No
red worm	Yes	No	No	No

As nouns, earthworm and red worm are synonyms defined as:

earthworm and red worm: terrestrial worm that burrows into and helps aerate soil; often surfaces when the ground is cool or wet; used as bait by anglers

Other synonyms of earthworm include angleworm, crawler, dew worm, fishing worm, fishworm, nightcrawler, nightwalker, wiggler.

earthworm (noun)	red worm (noun)
terrestrial worm that burrows into and helps aerate soil; often surfaces when the ground is cool or wet; used as bait by anglers	terrestrial worm that burrows into and helps aerate soil; often surfaces when the ground is cool or wet; used as bait by anglers