Stop, say, for a rest (5)
I believe the answer is:
break
This clue is a double definition.
'stop' is the first definition.
(synonyms)
'for a rest' is the second definition.
(I've seen this before)
'say' acts as a link.
(Other definitions for break that I've seen before include "Shatter; interval" , "Holiday - destroy" , "Interrupt - rest period" , "Come to an end" , "Vacation; snap" .)