Squeal about fine increasing (8)
I believe the answer is:
swelling
'increasing' is the definition.
(swelling is a kind of increasing)
'squeal about fine' is the wordplay.
'squeal' becomes 'sing' (both can mean to act as an informant).
'about' is an insertion indicator.
'fine' becomes 'well' ('well' can be similar in meaning to 'fine'**).
'sing' placed around 'well' is 'SWELLING'.
(Other definitions for swelling that I've seen before include "Lump" , "Nodule" , "Tumour" , "Abnormal enlargement" , "growing" .)