treat

from The American Heritage® Dictionary of the English Language, 5th Edition.

• intransitive verb To act or behave in a specified manner toward.
• intransitive verb To regard and handle in a certain way. Often used with as.
• intransitive verb To deal with in writing or speech; discuss.
• intransitive verb To deal with or represent artistically in a specified manner or style.
• intransitive verb To provide with food, entertainment, or gifts at one's own expense.
• intransitive verb To give (someone or oneself) something pleasurable.
• intransitive verb To subject to a process, action, or change, especially to a chemical or physical process or application.
• intransitive verb To give medical aid to (someone).
• intransitive verb To give medical aid to counteract (a disease or condition).
• intransitive verb To deal with a subject or topic in writing or speech. Often used with of.
• intransitive verb To pay for another's entertainment, food, or drink.
• intransitive verb To engage in negotiations, as to reach a settlement or agree on terms.
• noun Something, such as one's food or entertainment, that is paid for by someone else.
• noun A source of a special delight or pleasure.

from The Century Dictionary.

• In electricity, in the making of glow-lamps, to coat (the filament) with a deposited layer of carbon.
• noun A plaster or a salve made of wax, lard, etc., spread on cloth; a cerate.
• noun Parley; conference; treaty; discourse; discussion.
• noun An entertainment given as a compliment or expression of regard.
• noun Something given as an entertainment; something paid for in compliment to another.
• noun One's turn to treat (see treat, v. i., 3); especially, one of several rounds of drinks: as, it is my treat now.
• noun Anything which affords much pleasure; that which is peculiarly enjoyable; unusual gratification.
• noun An entreaty.
• To behave to or toward; conduct one's self in a certain manner with respect to; use.
• To discuss; discourse of; consider.
• To address; discourse to.
• To negotiate; settle.
• To handle, manipulate, or develop in any manner, especially in writing or speaking, or by any of the processes of art.
• To look upon; consider; regard.
• To manage in the application of remedies: as, to treat a fever or a patient.
• To sudject to the action of some chemical agent or reagent.
• To entertain; give a pleasure or treat to; especially, to entertain without expense to the recipient; give food or drink to, as a compliment or an expression of friendliness or regard.
• To entreat; beseech; solicit.
• To discourse; handle in writing or speaking; make discussion: formerly used absolutely, now followed usually by of, rarely by upon.
• To negotiate, especially for peace; discuss terms of accommodation: used absolutely or with a limiting phrase.
• To give an entertainment which costs the recipient nothing; especially, to bear the expense of food. drink, or any pleasure for another as a compliment or expression of good will. Compare to stand treat, under treat, n.

from the GNU version of the Collaborative International Dictionary of English.

• intransitive verb To discourse; to handle a subject in writing or speaking; to make discussion; -- usually with of.
• intransitive verb To negotiate; to come to terms of accommodation; -- often followed by with.
• intransitive verb To give a gratuitous entertainment, esp. of food or drink, as a compliment.
• transitive verb To handle; to manage; to use; to bear one's self toward
• transitive verb To discourse on; to handle in a particular manner, in writing or speaking.
• transitive verb To entertain with food or drink, especially the latter, as a compliment, or as an expression of friendship or regard.
• transitive verb obsolete To negotiate; to settle; to make terms for.
• transitive verb (Med.) To care for medicinally or surgically; to manage in the use of remedies or appliances.
• transitive verb To subject to some action; to apply something to.
• transitive verb obsolete To entreat; to beseech.
• noun obsolete A parley; a conference.
• noun An entertainment given as an expression of regard.
• noun That which affords entertainment; a gratification; a satisfaction.