Merriam-Webster's Collegiate® Dictionary, 11th Edition
TREAT
I. verb
Etymology: Middle English treten, from Anglo-French treter, traiter, traitier, from Latin tractare to drag about, handle, deal with, frequentative of trahere to drag, pull
Date: 14th century
intransitive verb to discuss terms of accommodation or settlement ; negotiate , to deal with a matter especially in writing ; discourse , to pay another's expenses (as for a meal or drink) especially as a compliment or as an expression of regard or friendship, transitive verb
1. to deal with in speech or writing ; expound , to present or represent artistically, to deal with ; handle ,
2. to bear oneself toward ; use , to regard and deal with in a specified manner,
3. to provide with free food, drink, or entertainment , to provide with enjoyment or gratification, to care for or deal with medically or surgically , to act upon with some agent especially to improve or alter , treater noun
II. noun
Date: 1651
1. an entertainment given without expense to those invited, the act of providing another with free food, drink, or entertainment , an especially unexpected source of joy, delight, or amusement