Burning tar by lounge (6)
I believe the answer is:
ablaze
'burning' is the definition.
(I've seen this before)
'tar by lounge' is the wordplay.
'tar' becomes 'ab'.
'by' is a charade indicator (letters next to each other).
'lounge' becomes 'laze' (as in to lounge or lie around).
'ab'+'laze'='ABLAZE'
(Other definitions for ablaze that I've seen before include "Flaming; on fire" , "Bright" , "burnt" , "On fire, burning" , "Fiery" .)