Radiant with Russian girl returning (5)
I believe the answer is:
aglow
'radiant' is the definition.
(I've seen this in another clue)
'with russian girl returning' is the wordplay.
'with' becomes 'w' (abbreviation).
'russian girl' becomes 'olga' (I've seen this before).
'returning' is a reversal indicator.
'w'+'olga'='wolga'
'wolga' back-to-front is 'AGLOW'.
(Other definitions for aglow that I've seen before include "to be exhibiting radiance" , "Lit up" , "emitting a steady light" , "Smouldering" , "Giving out a steady light" .)