mud stain vs stain

mud stain and stain both are nouns.

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

As nouns, stain is a hypernym of mud stain; that is, stain is a word with a broader meaning than mud stain:

Other hypernyms of mud stain include discoloration, discolouration.

mud stain (noun)	stain (noun)
a stain produced by mud	an act that brings discredit to the person who does it
	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

mud stain (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