staining vs stain

staining and stain both are nouns.

Word	Noun	Adjective	Verb	Adverb
staining	Yes	No	No	No
stain	Yes	No	Yes	No

staining (noun)	stain (noun)
(histology) the use of a dye to color specimens for microscopic study	an act that brings discredit to the person who does it
the act of spotting or staining something	a soiled or discolored appearance
	a symbol of disgrace or infamy
	anything regarded as making something unclean
	(microscopy) a dye or other coloring material that is used in microscopy to make structures visible

staining (verb)	stain (verb)
	produce or leave stains
	color with a liquid dye or tint
	color for microscopic study
	make dirty or spotty, as by exposure to air; also used metaphorically