What soldiers (at the double) say as they leave (2-2)
I believe the answer is:
ta-ta
'they leave' is the definition.
The definition suggests a singular noun which matches the answer.
'what soldiers at the double say' is the wordplay.
I cannot quite see how this works, but
'soldiers' could be 'ta' (abbreviation for Territorial Army) and 'ta' is located in the answer.
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is found within the answer.
A single letter 'a' remains which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
'as' is the link.
Can you help me to learn more?
(Other definitions for ta-ta that I've seen before include "Bye-bye" , "Cheerio" , "Adieu" , "A Farewell" , "Bye!" .)