Entertained a thought (6)

I believe the answer is:

amused

'entertained' is the definition.
(amusing is a kind of entertaining)

'a thought' is the wordplay.
'thought' becomes 'mused' (musing is a kind of thinking).
'a'+'mused'='AMUSED'

(Other definitions for amused that I've seen before include "Kept someone entertained" , "Pleasantly occupied" , "Tickled pink" , "Queen Victoria wasn't!" , "happily occupied" .)

I've seen this clue in The Telegraph.

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