Crossword Genius

Obstinate: hide when given new form mistress (1,3,2,3,4)

Ross

I believe the answer is:

a bit on the side

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

'obstinate hide when given new form mistress' is the definition.
I don't know anything about this answer so I can't tell whether this works.

'obstinate hide when given new form mistress' is the wordplay.
'obstinate hide' anagrams to 'A BIT ON THE SIDE'.
Though, I am not sure how this is indicated.

Can you help me to learn more?

(Other definitions for a bit on the side that I've seen before include "Mistress?" , "secret of a cheat?" , "as sauce on a plate?" , "that endangers union arrangements?" , "illicit lover" .)

I've seen this clue in The Guardian.
Want a hint initially instead of a full solution? Install my app