My word is annoying you at first (1,3)

I believe the answer is:

i say

'my word' is the definition.

'is annoying you at first' is the wordplay.
'at first' suggests taking the first letters.
The first letters of 'annoying you' is 'ay'.
'is'+'ay'='I SAY'

(Other definitions for i say that I've seen before include "That is surprising!" , "Dear me!" , "Comment from protestor" , "Exclamation of surprise" , "goodness!" .)

I've seen this clue in The Guardian.

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