Burning up, holding roman candle (5)
I believe the answer is:
torch
'candle' is the definition.
(thesaurus)
'burning up holding roman' is the wordplay.
'burning' becomes 'hot' ('hot' can be similar in meaning to 'burning').
'up' is a reversal indicator (in down clue: letters go upwards).
'holding' means one lot of letters goes inside another.
'roman' becomes 'rc' ('r.c.' can be a synonym of 'roman').
'hot' reversed gives 'toh'.
'toh' going around 'rc' is 'TORCH'.
(Other definitions for torch that I've seen before include "may get one glowing" , "Set fire to (something)" , "Light carried in the hand" , "Source of light" , "Such a love song" .)