Increase of former unease? (9)
I believe the answer is:
extension
'increase' is the definition.
(I know that extension is a type of enlargement)
'former unease?' is the wordplay.
'former' becomes 'ex' (prefix meaning former or onetime).
'unease?' becomes 'tension' (I can't explain this - if you can you should give a lot more credence to this answer).
'ex'+'tension'='EXTENSION'
'of' acts as a link.
Can you help me to learn more?
(Other definitions for extension that I've seen before include "Office phone, perhaps" , "Another phone" , "Annexe" , "new part of home?" , "telephone number" .)