Turning following law on old practice (7)

I believe the answer is:

flexure

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

'turning' is the definition.
(thesaurus)

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

(Other definitions for flexure that I've seen before include "Action of bending" , "Act of bending a joint" , "A bend" .)

I've seen this clue in The Sunday Times and The Times.

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