A mate mailed initial GIF, say (7)

I believe the answer is:

acronym

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'gif say' is the definition.
I can't judge whether this definition defines the answer.

'a mate mailed initial' is the wordplay.
'mate' becomes 'crony' (I've seen this before).
'initial' says to take the initial letters.
The initial letter of 'mailed' is 'm'.
'a'+'crony'+'m'='ACRONYM'

Can you help me to learn more?

(Other definitions for acronym that I've seen before include "radar, for one" , "Eg, Nato, Sars" , "Ernie, for one" , "UNESCO, say" , "Word made form first letters of other words" .)

I've seen this clue in the Sydney Morning Herald.

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