That chap’s greeting Mike (3)

I believe the answer is:

him

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'that chap's' is the definition.
I can't judge whether this definition defines the answer.

'greeting mike' is the wordplay.
'greeting' becomes 'hi' (hi is a kind of greeting).
'mike' becomes 'm' (phonetic alphabet: alpha, bravo, charlie etc.).
'hi'+'m'='HIM'

Can you help me to learn more?

(Other definitions for him that I've seen before include "Objective male pronoun" , "That man" , "Proper character" .)

I've seen this clue in The Times.

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