Popular fellow work outside making thin metal sheet (7)
I believe the answer is:
tinfoil
'thin metal sheet' is the definition.
'tinfoil' can be an answer for 'sheet' (tinfoil is a kind of sheet). I am not sure about the 'thin metal' bit.
'popular fellow work outside' is the wordplay.
'popular' becomes 'in' ('in' can mean trendy).
'fellow' becomes 'F' (abbreviation - of a society etc.).
'work' becomes 'toil' (toiling is a kind of working).
'outside' indicates putting letters inside.
'in'+'f'='inf'
'inf' put inside 'toil' is 'TINFOIL'.
'making' acts as a link.
Can you help me to learn more?
(Other definitions for tinfoil that I've seen before include "A help in the kitchen" , "Fine metal" , "Thin metal sheet for wrapping food etc" , "what can protect food" , "Kitchen item" .)