In Sun: it's a knitted bear! (7)
I believe the answer is:
sustain
'bear' is the definition.
(I've seen this before)
'in sun it's a knitted' is the wordplay.
'in' is an insertion indicator.
'knitted' is an anagram indicator (knit can mean to screw up or crease).
'its'+'a'='itsa'
'itsa' with letters rearranged gives 'stai'.
'sun' placed around 'stai' is 'SUSTAIN'.
(Other definitions for sustain that I've seen before include "Continue, prolong" , "Strengthen; suffer" , "Maintain" , "Bear (something's weight)" , "Endure" .)