Graduate arranged air-con for penguin (8)
I believe the answer is:
macaroni
'penguin' is the definition.
(macaroni is a type of penguin)
'graduate arranged air-con' is the wordplay.
'graduate' becomes 'ma' (abbreviation for Master of Arts).
'arranged' indicates anagramming the letters (letters rearranged).
'air'+'con'='aircon'
'aircon' anagrammed gives 'caroni'.
'ma'+'caroni'='MACARONI'
'for' is the link.
(Other definitions for macaroni that I've seen before include "Old dandy" , "Short thick tubes of pasta (8)" , "Type of pasta" , "Short narrow tubes of pasta" , "being a feather in Yankee's cap?" .)