When caught out, witch did a sketch and backed off (8)
I believe the answer is:
withdrew
'when caught out witch did a sketch' is the definition.
I can't tell whether this defines the answer.
'and backed off' is the wordplay.
'and' becomes 'with'.
'backed off' becomes 'drew' (I can't justify this - if you can you should believe this answer much more).
'with'+'drew'='WITHDREW'
Can you help me to learn more?
(Other definitions for withdrew that I've seen before include "Backed away or bowed out" , "Took away; retreated" , "retired" , "Took back" , "Scratched" .)