Staggered in front of ship at the French seaport (6,4)
I believe the answer is:
bowled over
'staggered' is the definition.
The answer and definition can be both related to thinking as well as being past participle verbs.
Maybe you can see an association between them that I don't see?
'front of ship at the french seaport' is the wordplay.
'front of ship' becomes 'bow' (term for the front of a ship).
'at' is a charade indicator (letters next to each other).
'the french' becomes 'le' ('the' in French).
'seaport' becomes 'dover' (I can't justify this - if you can you should give a lot more credence to this answer).
'bow'+'le'+'dover'='BOWLED OVER'
'in' is the link.
Can you help me to learn more?
(Other definitions for bowled over that I've seen before include "made several deliveries" , "Hit for six" , "Greatly impressed" , "having briefly joined attack" , "Overwhelmed" .)