Robs new sphere (3)
I believe the answer is:
orb
'sphere' is the definition.
(I know that orb is a type of sphere)
'rob's new' is the wordplay.
'new' indicates an anagram.
'rob' with letters rearranged gives 'ORB'.
(Other definitions for orb that I've seen before include "Jewelled ornament" , "Spherical object or shape" , "The World" , "ball with cross" , "Ornamental sphere" .)