Merriam-Webster's Collegiate® Dictionary, 11th Edition
SLUR
I. noun
Etymology: obsolete English dialect slur thin mud, from Middle English sloor; akin to Middle High German slier mud
Date: 1609
1. an insulting or disparaging remark or innuendo ; aspersion , a shaming or degrading effect ; stain , stigma , a blurred spot in printed matter ; smudge ,
II. verb (slurred; slurring)
Date: 1660
transitive verb to cast aspersions on ; disparage , to make indistinct ; obscure , intransitive verb to slip so as to cause a slur,
III. verb (slurred; slurring)
Etymology: probably from Low German slurrn to shuffle; akin to Middle English sloor mud
Date: 1660
transitive verb
1. to slide or slip over without due mention, consideration, or emphasis , to perform hurriedly ; skimp , to perform (successive tones of different pitch) in a smooth or connected manner,
3. to reduce, make a substitution for, or omit (sounds that would normally occur in an utterance), to utter with such reduction, substitution, or omission of sounds , intransitive verb slip , slide , drag , shuffle ,
IV. noun
Date: circa 1801
1. a curved line connecting notes to be sung to the same syllable or performed without a break, the combination of two or more slurred tones, a slurring manner of speech