A jersey, perhaps, an item of underwear found in the meadow (7)
I believe the answer is:
cowslip
'the meadow' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how one could define the other.
'a jersey perhaps an item of underwear' is the wordplay.
'a jersey perhaps' becomes 'cows' (jersey is a kind of cows).
'an item of underwear' becomes 'lip' (I can't justify this - if you can you should give a lot more credence to this answer).
'cows'+'lip'='COWSLIP'
'found in' acts as a link.
Can you help me to learn more?
(Other definitions for cowslip that I've seen before include "Type of primrose" , "Yellow wild flower" , "Wild spring flower" , "Wild yellow primula" , "bloomer" .)