Repeated thanks for wrapping fluorine and iron in silk (7)
I believe the answer is:
taffeta
'silk' is the definition.
(I've seen this before)
'repeated thanks for wrapping fluorine and iron' is the wordplay.
'repeated thanks' becomes 'tata' (I can't explain this - if you can you should give a lot more credence to this answer).
'for wrapping' indicates putting letters inside (inserted letters are wrapped up).
'fluorine' becomes 'F' (chemical symbol).
'and' means one lot of letters go next to another.
'iron' becomes 'Fe' (chemical symbol for iron).
'f'+'fe'='ffe'
'tata' going around 'ffe' is 'TAFFETA'.
'in' is the link.
Can you help me to learn more?
(Other definitions for taffeta that I've seen before include "Thin glossy silk fabric" , "Thin silky material" , "Stiff, silky fabric" , "Fine crisp silk fabric" , "Sheeny fabric" .)