A picked container? (6)
I believe the answer is:
'container?' is the definition.
(pocket is a kind of container)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for pocket that I've seen before include "Pot a snooker ball into the ....." , "One of six pouches on snooker table" , "A ball-catching pouch on a snooker table" , "Electronic maths aid" , "Snooker ball should go into the ......" .)