Record-holder, somewhat egotistical, bumptious (5)
I believe the answer is:
album
'record-holder' is the definition.
(album is a type of record)
'somewhat egotistical bumptious' is the wordplay.
'somewhat' says the answer is hidden in the clue.
'ALBUM' is hidden in the letters of 'egotistical bumptious'.
(Other definitions for album that I've seen before include "Book for displaying a collection" , "Item of music released" , "place for photos" , "Book for, eg, stamps" , "Scrapbook, for stamps or photographs" .)