roll-on vs dispenser

roll-on and dispenser both are nouns.

Word	Noun	Adjective	Verb	Adverb
roll-on	Yes	No	No	No
dispenser	Yes	No	No	No

As nouns, dispenser is a hypernym of roll-on; that is, dispenser is a word with a broader meaning than roll-on:

roll-on: a dispenser of a liquid cosmetic (such as a deodorant) having a revolving ball as an applicator
dispenser: a container so designed that the contents can be used in prescribed amounts

roll-on (noun)	dispenser (noun)
a woman's foundation garment rolled on to the hips	a container so designed that the contents can be used in prescribed amounts
a dispenser of a liquid cosmetic (such as a deodorant) having a revolving ball as an applicator	a person who dispenses