Brother wearing several reduced pink hats (9)
I believe the answer is:
sombreros
'hats' is the definition.
(sombrero is a kind of hat)
'brother wearing several reduced pink' is the wordplay.
'brother' becomes 'br'.
'wearing' means one lot of letters goes inside another.
'several' becomes 'some' ('some' can be similar in meaning to 'several'**).
'reduced' means to remove the last letter.
'pink' becomes 'rosy' (I've seen this before).
'br' placed into 'some' is 'sombre'.
'rosy' with its last letter taken off is 'ros'.
'sombre'+'ros'='SOMBREROS'
(Another definition for sombreros that I've seen is " Mexican hats".)