A source of light (6)
I believe the answer is:
candle
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">a source of light</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for candle that I've seen before include "Wax light source" , "Artificial light" , "Old form of illumination" , "Waxy light source" , "may be too expensive for game" .)