Boy cut all gorging, ankles progressively swelling (5)

I believe the answer is:

bulge

'swelling' is the definition.
(thesaurus)

I cannot understand how the rest of the clue works.

(Other definitions for bulge that I've seen before include "Battle of the -----: last major German counter-offensive of WWII (1944)" , "Protrude" , "Rounded swelling" , "Hitler's offensive" , "surge?" .)

I've seen this clue in The Independent.

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