Let go by Bottom after pressure to get out of bed (4,2)
I believe the answer is:
pass up
'let go by' is the definition.
(thesaurus)
'bottom after pressure to get out of bed' is the wordplay.
'bottom' becomes 'ass' ('ass' can be a synonym of 'bottom'**).
'after' is a charade indicator (letters next to each other).
'pressure' becomes 'p' (abbreviation).
'to get' is a charade indicator (letters next to each other).
'out of bed' becomes 'up' ('up' can be a synonym of 'out of bed').
'ass' put after 'p' is 'pass'.
'pass'+'up'='PASS UP'
(Other definitions for pass up that I've seen before include "Refrain from taking an opportunity" , "Miss" , "Turn (something) down" , "forego" , "Neglect (an opportunity)" .)