Stay behind in mid-spring (5)
I believe the answer is:
dwell
'stay' is the definition.
(I've seen this in another clue)
'behind in mid-spring' is the wordplay.
'behind in' says to take the final letters.
'spring' becomes 'well' (both can mean a source of water).
The last letter of 'mid' is 'd'.
'd'+'well'='DWELL'
(Other definitions for dwell that I've seen before include "Abide, reside" , "Think moodily (on something)" , "Live (in a place)" , "Harp" , "Exist (within)" .)