What does "treat" mean?

Additional senses

1. 2.To entertain with food or drink, especially the latter, as a compliment, or as an expression of friendship or regard; as, to treat the whole company.
2. 3.To negotiate; to settle; to make terms for. [Obs.] To treat the peace, a hundred senators Shall be commissioned. Dryden.
3. 4.(Med.) To care for medicinally or surgically; to manage in the use of remedies or appliances; as, to treat a disease, a wound, or a patient.
4. 5.To subject to some action; to apply something to; as, to treat a substance with sulphuric acid. Ure.
5. 6.To entreat; to beseech. [Obs.] Ld. Berners.
6. 7.To discourse; to handle a subject in writing or speaking; to make discussion; -- usually with of; as, Cicero treats of old age and of duties. And, shortly of this story for to treat. Chaucer. Now of love they treat. Milton.
7. 8.To negotiate; to come to terms of accommodation; -- often followed by with; as, envoys were appointed to treat with France. Inform us, will the emperor treat! Swift.
8. 9.To give a gratuitous entertainment, esp. of food or drink, as a compliment.
9. 10.A parley; a conference. [Obs.] Bid him battle without further treat. Spenser.
10. 11.An entertainment given as an expression of regard.
11. 12.That which affords entertainment; a gratification; a satisfaction; as, the concert was a rich treat.