ALALLL? That's considering everything! (3,2,3)
I believe the answer is:
all in all
'alalll?' is the definition.
I can't tell whether this defines the answer.
'considering everything' is the wordplay.
'considering' becomes 'allin' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'everything' becomes 'all' (I've seen this before).
'allin'+'all'='ALL IN ALL'
'that's' acts as a link.
Can you help me to learn more?
(Other definitions for all in all that I've seen before include "Taken as a whole, everything considered" , "As a whole, considering everything" , "Taking everything into consideration" , "in summary" .)