softener vs conditioner

softener and conditioner both are nouns.

Word	Noun	Adjective	Verb	Adverb
softener	Yes	No	No	No
conditioner	Yes	No	No	No

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

softener: a substance added to another to make it less hard
conditioner: a substance used in washing (clothing or hair) to make things softer

Other hyponyms of softener include plasticiser, plasticizer, water softener.

softener (noun)	conditioner (noun)
a substance added to another to make it less hard	exercise that conditions the body
	a substance used in washing (clothing or hair) to make things softer
	a trainer of athletes