Cheerful, getting out of bed tired? (6)
I believe the answer is:
upbeat
'cheerful' is the definition.
(I know that cheerful can be written as upbeat)
'out of bed tired?' is the wordplay.
'out of bed' becomes 'up' (synonyms).
'tired?' becomes 'beat' ('beat' can be similar in meaning to 'tired').
'up'+'beat'='UPBEAT'
'getting' acts as a link.
(Other definitions for upbeat that I've seen before include "Cheerful and encouraging, like lively music" , "Conductor's beginning" , "Relentlessly optimistic" , "maestro communicates this to orchestra" , "Cheerful - positive about the future" .)