Tumours in significant ratio linked to college (6)
I believe the answer is:
polypi
'tumours' is the definition.
The answer and definition can be both states of affairs as well as being plural nouns.
Perhaps you can see a link between them that I can't see?
'significant ratio linked to college' is the wordplay.
'significant ratio' becomes 'pi' (I can't explain this - if you can you should give a lot more credence to this answer).
'linked to' is a charade indicator (letters next to each other).
'college' becomes 'poly' (polytechnic).
'pi' put after 'poly' is 'POLYPI'.
'in' is the link.
Can you help me to learn more?
(Another definition for polypi that I've seen is " Growth more than once".)