Well, jump! (6)
I believe the answer is:
spring
This clue is a double definition.
'well' is the first definition.
(a well is a spring of water)
'jump' is the second definition.
(spring is a kind of jump)
(Other definitions for spring that I've seen before include "Leap - opposite to 15" , "Leap - part of year" , "May, perhaps - bound" , "bound to > become warped" , "Jump up in early season" .)