Candle part (4)
I believe the answer is:
wick
'candle part' is the definition.
('wick' is part of 'candle')
This is all the clue.
(Other definitions for wick that I've seen before include "Length of thread in centre of candle" , "Caithness seaport" , "that burns down?" , "light fibre" , "Caithness fishing town - part of candle" .)