Charges about having lost good rifle (6)

I believe the answer is:

'rifle' is the definition.
(thesaurus)

I don't understand the rest of the clue.

(Other definitions for search that I've seen before include "thorough examination" , "Showing pleasure" , "Look through - arches (anag)" , "Try to locate" , "What examiners do" .)

I've seen this clue in The Guardian.

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