Bother! It's a puff ball! (3)
I believe the answer is:
ado
'bother' is the definition.
(thesaurus)
'a puff ball' is the wordplay.
'a puff' becomes 'ad'.
'ball' becomes 'o'.
'ad'+'o'='ADO'
'it's' is the link.
(Other definitions for ado that I've seen before include "Hoo-ha" , "Nothing caused much around 1598" , "Fuss or bustle" , "Song and dance" , "Fuss, bother" .)