It means goodbye (2-2)
I believe the answer is:
ta-ta
'goodbye' is the definition.
(I've seen this before)
'it' is the wordplay.
I cannot really understand how this works, but
'it' could be 't' (abbreviation. e.g. in 'tis) and 't' is located in the answer.
The remaining letters 'ata' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
'means' is the link.
Can you help me to learn more?
(Other definitions for ta-ta that I've seen before include "Adieu" , "Bye!" , "A Farewell" , "Bye-bye" , "Cheerio" .)