devilfish vs octopus

devilfish and octopus both are nouns.

Word	Noun	Adjective	Verb	Adverb
devilfish	Yes	No	No	No
octopus	Yes	No	No	No

As nouns, devilfish and octopus are synonyms defined as:

devilfish and octopus: bottom-living cephalopod having a soft oval body with eight long tentacles

devilfish (noun)	octopus (noun)
extremely large pelagic tropical ray that feeds on plankton and small fishes; usually harmless but its size make it dangerous if harpooned	bottom-living cephalopod having a soft oval body with eight long tentacles
bottom-living cephalopod having a soft oval body with eight long tentacles	tentacles of octopus prepared as food
medium-sized greyish-black whale of the northern Pacific