Out of bed and ready for trouble (5)
I believe the answer is:
upset
'trouble' is the definition.
(upset can mean trouble or controversy)
'out of bed and ready' is the wordplay.
'out of bed' becomes 'up' (synonyms).
'and' says to put letters next to each other.
'ready' becomes 'set' (similar in meaning).
'up'+'set'='UPSET'
'for' acts as a link.
(Other definitions for upset that I've seen before include "Overturn, disturb" , "Overturn; unhappy" , "Disturb, physically or emotionally" , "bug" , "Distressed; overturn" .)