Pierce Brosnan's rear clad in frilly material (5)
I believe the answer is:
lance
'pierce' is the definition.
(I know that lance is a kind of pierce)
'brosnan's rear clad in frilly material' is the wordplay.
'rear' says to take the final letters (the back of the word).
'clad in' is an insertion indicator.
'frilly material' becomes 'lace' (I've seen this in another clue).
The final letter of 'brosnan' is 'n'.
'n' inserted into 'lace' is 'LANCE'.
(Other definitions for lance that I've seen before include "Surgical knife" , "Weapon of knights of old" , "A horse soldier's spear" , "Knightly weapon" , "Spear for a horse-soldier" .)