Wave on racetrack to indicate safety device intended to prevent fire (7,7)
I believe the answer is:
circuit breaker
'indicate safety device intended to prevent fire' is the definition.
I can't tell whether this defines the answer.
'wave on racetrack' is the wordplay.
'wave' becomes 'breaker' (breaker is a kind of wave).
'on' means one lot of letters go next to another.
'racetrack' becomes 'circuit' (synonyms).
'breaker' put after 'circuit' is 'CIRCUIT-BREAKER'.
'to' acts as a link.
Can you help me to learn more?
(Other definitions for circuit breaker that I've seen before include "may interrupt a signal" , "means to detach from current" , "power cut-off" , "Electric safety device" .)