Old-fashioned, but having all the angles (6)

I believe the answer is:

square

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

'old-fashioned' is the definition.
(I've seen this before)

I don't understand the rest of the clue.

(Other definitions for square that I've seen before include "area of town" , "Regular figure" , "- Leg; - meal; - root" , "See 19" , "Old-fashioned - fix" .)

I've seen this clue in the Evening Standard.

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