serpent vs blind snake

serpent and blind snake both are nouns.

Word	Noun	Adjective	Verb	Adverb
serpent	Yes	No	No	No
blind snake	Yes	No	No	No

As nouns, blind snake is a hyponym of serpent; that is, blind snake is a word with a more specific, narrower meaning than serpent:

Other hyponyms of serpent include colubrid, colubrid snake, worm snake, constrictor, elapid, elapid snake, sea snake, viper.

serpent (noun)	blind snake (noun)
limbless scaly elongate reptile; some are venomous	wormlike burrowing snake of warm regions having vestigial eyes
an obsolete bass cornet; resembles a snake
a firework that moves in serpentine manner when ignited