slur

A blemish made by dirt.

A disparaging remark.

“it is difficult for a woman to understand a man's sensitivity to any slur on his virility”

(music) a curved line spanning notes that are to be played legato.

Become vague or indistinct.

Play smoothly or legato.

“the pianist slurred the most beautiful passage in the sonata”

Speak disparagingly of; e.g., make a racial slur.

“your comments are slurring your co-workers”

Utter indistinctly.