Truncheon William shortened, adding wedge perhaps (5,4)

I believe the answer is:

billy club

'truncheon' is the definition.
(I know that truncheon can be written as billy club)

'william shortened adding wedge perhaps' is the wordplay.
'william shortened' becomes 'Billy' (Billy is short for William).
'adding' means one lot of letters go next to another.
'wedge perhaps' becomes 'club' (wedge is a kind of club).
'billy'+'club'='BILLY CLUB'

I've seen this clue in The Guardian.

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