mattress vs palliasse

mattress and palliasse both are nouns.

Word	Noun	Adjective	Verb	Adverb
mattress	Yes	No	No	No
palliasse	Yes	No	No	No

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

mattress: a large thick pad filled with resilient material and often incorporating coiled springs, used as a bed or part of a bed
palliasse: mattress consisting of a thin pad filled with straw or sawdust

Other hyponyms of mattress include air mattress, feather bed, featherbed, futon, paillasse, pallet, spring mattress, tick.

mattress (noun)	palliasse (noun)
a large thick pad filled with resilient material and often incorporating coiled springs, used as a bed or part of a bed	mattress consisting of a thin pad filled with straw or sawdust