Burglars initially lie about fire (5)
I believe the answer is:
blaze
'fire' is the definition.
(I know that blaze is a type of fire)
'burglars initially lie about' is the wordplay.
'initially' suggests taking the first letters.
'lie about' becomes 'laze' (I've seen this in another clue).
The initial letter of 'burglars' is 'b'.
'b'+'laze'='BLAZE'
(Other definitions for blaze that I've seen before include "Strong fire" , "Strong flame burning brightly" , "Fire -- stripe on a horse's head" , "Sensationally announce" , "Pioneer" .)