Peak time before break (7)
I believe the answer is:
everest
'peak' is the definition.
(I know that Everest is a mountain peak)
'time before break' is the wordplay.
'time before' becomes 'eve' (the eve of something is the night before).
'break' becomes 'rest' (a rest is taking a break).
'eve'+'rest'='EVEREST'
(Other definitions for everest that I've seen before include "Great achievement" , "A high spot" , "Highest Himalayan mountain" , "Mountain on the Nepal-Tibet border" , "Highest peak" .)