Twist about with pain then wither away (6)
I believe the answer is:
writhe
'twist' is the definition.
(I know that twist can be written as writhe)
'with pain then wither away' is the wordplay.
'wither' anagrams to 'WRITHE'.
But, I'm not sure how this is indicated.
'about' acts as a link.
Can you help me to learn more?
(Other definitions for writhe that I've seen before include "Wriggle" , "Move sinuously" , "'Twist, squirm (6)'" , "feel acute embarrassment" , "Thrash" .)