Swell cheese creation, ultimately something Cheddar is famous for (7)
I believe the answer is:
engorge
'swell' is the definition.
(both can mean to grow in size)
'cheese creation ultimately something cheddar is famous for' is the wordplay.
'ultimately' suggests the final letters.
'something cheddar is famous for' becomes 'gorge' (Cheddar Gorge in Somerset).
The last letters of 'cheese creation' are 'en'.
'en'+'gorge'='ENGORGE'
(Other definitions for engorge that I've seen before include "Eat ravenously" , "Swell with blood, water, etc" , "Congest with blood - eat greedily" , "Cause to swell with fluid" , "Guzzle" .)