Duenna took half of them away because of this (3,2)
I believe the answer is:
due to
'them away because of this' is the definition.
The definition suggests a singular noun but the answer is not.
'duenna took half' is the wordplay.
'duenna' becomes 'due' (I can't explain this - if you can you should believe this answer much more).
'half' means to take half the letters.
'took' with half the letters taken is 'to'.
'due'+'to'='DUE TO'
'of' is the link.
Can you help me to learn more?
(Another definition for due to that I've seen is " Caused by".)