Blues singer Rush (4)

I believe the answer is:

otis

(Other definitions for otis that I've seen before include "Regretful miss" , "- - Redding (soul music star)" , "-- Redding, US singer" , "Miss -- Regrets, Cole Porter song" , "Cole Porter's miss who was "unable to lunch today"" .)

I've seen this clue in the USA Today.

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