King perhaps was concerned with English loss (4)
I believe the answer is:
card
'king perhaps' is the definition.
(king is a type of playing card)
I cannot understand how the remainder of the clue works.
(Other definitions for card that I've seen before include "Something (usually) folded with a special message" , "Stiff paper; plastic money" , "caution" , "One taken in hand" , "Posted greeting" .)