Grannie, eager to find a cotton cloth (7)
I believe the answer is:
nankeen
'a cotton cloth' is the definition.
(I've seen this before)
'grannie eager' is the wordplay.
'grannie' becomes 'nan' (I've seen this before).
'eager' becomes 'keen' (I've seen this before).
'nan'+'keen'='NANKEEN'
'to find' is the link.
(Other definitions for nankeen that I've seen before include "Chinese cotton cloth" , "mustard colour" , "Buff colour" , "Buff-coloured cotton cloth" , "Buff-coloured cotton fabric" .)