Cotton fabric: there’s concern after losing a large amount (8)
I believe the answer is:
cretonne
'cotton fabric' is the definition.
(I've seen this before)
'concern after losing a large amount' is the wordplay.
'concern' becomes 'care' (synonyms).
'after losing' is a deletion indicator.
'large amount' becomes 'tonne'.
'care' with 'a' taken away is 'cre'.
'cre'+'tonne'='CRETONNE'
'there's' is the link.
(Other definitions for cretonne that I've seen before include "Heavy (floral) cotton fabric" , "Heavy fabric used for furnishing" , "Heavy fabric used for furniture covers and curtains" , "Type of cotton fabric" , "Fabric used for upholstery" .)