Collapsible shield? (7)
I believe the answer is:
buckler
'shield?' is the definition.
(I know that buckler can be written as buckler)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for buckler that I've seen before include "Small round shield" , "likely to give way under pressure?" , "gives way under pressure?" , "Small shield for the forearm" .)