botulin vs botulinus toxin

botulin and botulinus toxin both are nouns.

Word	Noun	Adjective	Verb	Adverb
botulin	Yes	No	No	No
botulinus toxin	Yes	No	No	No

As nouns, botulin and botulinus toxin are synonyms defined as:

botulin and botulinus toxin: potent bacterial toxin produced by the bacterium Clostridium botulinum that causes botulism; can be used as a bioweapon

Other synonyms of botulin include botulismotoxin.

botulin (noun)	botulinus toxin (noun)
potent bacterial toxin produced by the bacterium Clostridium botulinum that causes botulism; can be used as a bioweapon	potent bacterial toxin produced by the bacterium Clostridium botulinum that causes botulism; can be used as a bioweapon