Negotiate entertainment for free (5)

I believe the answer is:

treat

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

'negotiate' is the definition.
(I've seen this before)

I cannot understand how the rest of the clue works.

(Other definitions for treat that I've seen before include "An indulgence; handle" , "Deal with - source of great pleasure" , "Deal with sickness" , "could be a feast" , "Indulgence; deal with" .)

I've seen this clue in The Telegraph.

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