Dandy's bulge (5)

I believe the answer is:

swell

This clue is a double definition.

'dandy's' is the first definition.
('swell' can be a synonym of 'dandy')

'bulge' is the second definition.
(thesaurus)

(Other definitions for swell that I've seen before include "Enlargement when liquid accumulates" , "Rise into waves" , "VIP?" , "Become larger in size" , "mushroom" .)

I've seen this clue in The Telegraph.

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