Split wood brought back and lit finally (4)
I believe the answer is:
rift
'split' is the definition.
(I've seen this before)
'wood brought back and lit finally' is the wordplay.
'wood' becomes 'fir' (fir is a kind of wood**).
'brought back' says the letters should be written backwards.
'and' says to put letters next to each other.
'finally' indicates one should take the final letters.
The final letter of 'lit' is 't'.
'fir' backwards is 'rif'.
'rif'+'t'='RIFT'
(Other definitions for rift that I've seen before include "opening" , "Breach or quarrel" , "Breach; crack" , "Lack of harmony" , "Cleft or fissure" .)