Second son in Cambridge colleges area (5)

I believe the answer is:

backs

I'm a little stuck... Click here to teach me more about this clue!

'cambridge colleges area' is the definition.
I can't tell whether this definition defines the answer.

'second son' is the wordplay.
'second' becomes 'back' (to second a motion is to back it).
'son' becomes 's' (genealogical abbreviation for son).
'back'+'s'='BACKS'

'in' acts as a link.

Can you help me to learn more?

(Other definitions for backs that I've seen before include "delightful Cambridge area" , "Helps or supports with money" , "Defenders" , "champions" , "Defensive players" .)

I've seen this clue in The Sun.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.