tentacle vs barbel

tentacle and barbel both are nouns.

Word	Noun	Adjective	Verb	Adverb
tentacle	Yes	No	No	No
barbel	Yes	No	No	No

As nouns, barbel is a hyponym of tentacle; that is, barbel is a word with a more specific, narrower meaning than tentacle:

tentacle: any of various elongated tactile or prehensile flexible organs that occur on the head or near the mouth in many animals; used for feeling or grasping or locomotion
barbel: slender tactile process on the jaws of a fish

Other hyponyms of tentacle include antenna, feeler, feeler.

tentacle (noun)	barbel (noun)
any of various elongated tactile or prehensile flexible organs that occur on the head or near the mouth in many animals; used for feeling or grasping or locomotion	slender tactile process on the jaws of a fish
something that acts like a tentacle in its ability to grasp and hold