Scot partnering Beth in play (3)

I believe the answer is:

mac

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

'scot' is the definition.
(many Scottish surnames begin with Mac)

I don't understand how the remainder of the clue works.

Can you help me to learn more?

(Other definitions for mac that I've seen before include "Waterproof raincoat, in short" , "PC" , "Coat - computer" , "Raincoat (colloq.)" , "It may help you keep dry" .)

Want a hint initially instead of a full solution? Install my app