Old King's lecturer, say, resident in it? (7)
I believe the answer is:
college
'old' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.
'king's lecturer say resident in it?' is the wordplay.
'king' becomes 'cole' (I've seen this before).
'lecturer' becomes 'l'.
'say resident' becomes 'eg' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'in it?' means one lot of letters goes inside another.
'l'+'eg'='leg'
'cole' placed around 'leg' is 'COLLEGE'.
Can you help me to learn more?
(Other definitions for college that I've seen before include "Place of higher education" , "Where to train" , "SECOND PART OF 20" , "School" , "Educational institution" .)