Lover's meeting in tree (4)
I believe the answer is:
I believe this clue is a triple definition!
'lover's' is the first definition.
'meeting' is the second definition.
(date is a kind of meeting)
'in' acts as a link.
'tree' is the third definition.
(I've seen this before)
(Other definitions for date that I've seen before include "Step out with" , "A social appointment - check calendar" , "Particular time of event - fruit" , "Sweet edible fruit" , "Assignation; fruit" .)