"Smooth" singer Thomas (3)
I believe the answer is:
rob
'smooth singer thomas' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for rob that I've seen before include "Unlawfully take property from (someone)" , "Take something without the owner's consent" , "boy's name" , "Hold up" , "Burgle" .)