A kid relaxed (2,4)

I believe the answer is:

at ease

'relaxed' is the definition.
(similar in meaning)

'a kid' is the wordplay.
'kid' becomes 'tease' (both can mean to mock).
'a'+'tease'='AT EASE'

(Other definitions for at ease that I've seen before include "Free from discomfort - that's an order" , "Free from anxiety" , "unworried" , "Comfortable" , "In a relaxed attitude" .)

I've seen this clue in The Times.

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