Crossword Genius

Chum, say, keeps near sons to watch them (4-3)

Ross

I believe the answer is:

baby-sit

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

'chum say' is the definition.
Although both the answer and definition are verbs in their base form, I can't understand how they can define each other.

'near sons to watch them' is the wordplay.
I cannot really understand how this works, but
'near' could be 'by' (near means close by) and 'by' is located in the answer.
'sons' could be 's' and 's' is found in the answer.
The remaining letters 'bait' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...

'keeps' acts as a link.

Can you help me to learn more?

(Other definitions for baby-sit that I've seen before include "Look after young children" , "Mind small children while parents have a night out" , "Take charge to allow parents to go out" , "Look after youngsters" , "Look after children temporarily" .)

I've seen this clue in The Independent.
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.