bistre vs bister

bistre and bister both are nouns.

Word	Noun	Adjective	Verb	Adverb
bistre	Yes	No	No	No
bister	Yes	No	No	No

As nouns, bistre and bister are synonyms defined as:

bistre and bister: a water-soluble brownish-yellow pigment made by boiling wood soot

bistre (noun)	bister (noun)
a water-soluble brownish-yellow pigment made by boiling wood soot	a water-soluble brownish-yellow pigment made by boiling wood soot