Go out to pee in the morning over large tree (4,4)
I believe the answer is:
date palm
'tree' is the definition.
(date palm is a kind of tree)
'go out to pee in the morning over large' is the wordplay.
'go out' becomes 'date' (dating is a kind of going out).
'to pee' becomes 'p'.
'in the morning' becomes 'am'.
'over' indicates putting letters inside.
'large' becomes 'l'.
'am' going around 'l' is 'alm'.
'date'+'p'+'alm'='DATE PALM'
(Other definitions for date palm that I've seen before include "subtropical tree" , "Tree bearing fruit with stones" , "that can bear fruit" , "Tree with sweet fruit" , "Fruit-bearing tree" .)