Comparatively worthless piece to offer as security (4)
I believe the answer is:
pawn
'security' is the definition.
(I've seen this before)
'comparatively worthless piece to offer' is the wordplay.
I cannot quite see how this works, but
'piece' could be 'paw' (paw is a kind of piece) and 'paw' is found in the answer.
A single letter 'n' remains which might be clued in a way I don't understand.
This explanation may well be incorrect...
'as' acts as a link.
Can you help me to learn more?
(Other definitions for pawn that I've seen before include "Minor chessman" , "Deposit as security for a loan" , "Hock; cat's-paw" , "Deposit as pledge" , "Lodge (item) for money" .)