Boxer grabbing an Indian every so often is joking (7)

I believe the answer is:

punning

'joking' is the definition.
(punning is a kind of joking)

'boxer grabbing an indian every so often' is the wordplay.
'boxer' becomes 'pug' (short for pugilist - term for boxer).
'grabbing' is an insertion indicator.
'every so often' indicates alternate letters.
'an'+'indian'='anindian'
The alternate letters of 'anindian' are 'nnin'.
'pug' enclosing 'nnin' is 'PUNNING'.

'is' acts as a link.

(Another definition for punning that I've seen is " Making a play on words".)

I've seen this clue in The Times.

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