long pillow vs bolster

long pillow and bolster both are nouns.

Word	Noun	Adjective	Verb	Adverb
long pillow	Yes	No	No	No
bolster	Yes	No	Yes	No

As nouns, long pillow and bolster are synonyms defined as:

long pillow and bolster: a pillow that is often put across a bed underneath the regular pillows

long pillow (noun)	bolster (noun)
a pillow that is often put across a bed underneath the regular pillows	a pillow that is often put across a bed underneath the regular pillows

long pillow (verb)	bolster (verb)
	add padding to
	support and strengthen
	prop up with a pillow or bolster