See dame boarding sub last (2,3,6)
I believe the answer is:
lo and behold
'see' is the definition.
I know nothing about this answer so I can't judge whether this works.
'dame boarding sub last' is the wordplay.
'dame' becomes 'DBE' (Dame of the British Empire).
'boarding' means one lot of letters goes inside another.
'sub' becomes 'loan' (British term for advance against income).
'last' becomes 'hold' (I can't justify this - if you can you should give a lot more credence to this answer).
'loan'+'hold'='loanhold'
'dbe' placed into 'loanhold' is 'LO AND BEHOLD'.
Can you help me to learn more?
(Other definitions for lo and behold that I've seen before include "what a wonderful thing" , "This is new!" .)