Seize ball from captain with trophy? Yes! (6)
I believe the answer is:
occupy
'seize' is the definition.
(thesaurus)
'ball from captain with trophy? yes' is the wordplay.
'ball from captain' becomes 'oc' (I can't justify this - if you can you should give a lot more credence to this answer).
'with' means one lot of letters go next to another.
'trophy?' becomes 'cup' (cup is a kind of trophy).
'yes' becomes 'y'.
'oc'+'cup'+'y'='OCCUPY'
Can you help me to learn more?
(Other definitions for occupy that I've seen before include "Employ" , "Hold; tenant" , "Take over - live in" , "Reside in; keep busy" , "'Fill a position, reside (6)'" .)