Stretch over, has a rest (4)
I believe the answer is:
naps
'has a rest' is the definition.
I can't tell whether this definition defines the answer.
'stretch over' is the wordplay.
'stretch' becomes 'span' (I've seen this in another clue).
'over' says the letters should be written in reverse.
'span' back-to-front is 'NAPS'.
Can you help me to learn more?
(Other definitions for naps that I've seen before include "Span including short sleeps" , "Takes forty winks" , "Tips; sleeps" , "Snoozes" .)