slur vs refer

slur is a noun but refer is not a noun.

Word	Noun	Adjective	Verb	Adverb
slur	Yes	No	Yes	No
refer	No	No	Yes	No

As verbs, refer is a hypernym of slur; that is, refer is a word with a broader meaning than slur:

Other hypernyms of slur include denote.

slur (noun)	refer (noun)
a blemish made by dirt
a disparaging remark
(music) a curved line spanning notes that are to be played legato

slur (verb)	refer (verb)
become vague or indistinct	think of, regard, or classify under a subsuming principle or with a general group or in relation to another
utter indistinctly	have as a meaning
speak disparagingly of; e.g., make a racial slur	make reference to
play smoothly or legato	use a name to designate
	seek information from
	send or direct for treatment, information, or a decision
	be relevant to