treat-n; 3 Senses

Sense Number 1: a delectable, delicious serving of food, often sweet

Commentary: TREAT[+entity][+food][+serving][+delectable]

The chef has whipped up some rich chocolate treats for the dessert menu.
We ran out of treats on Halloween night and had to ask the neighbors for some extra.
The dog knows how to shake hands and roll over for a treat.
The children got ice cream for a treat after the movie.

WordNet 3.0 Sense Numbers: 1

Sense Number 2: a very pleasurable occasion

Commentary: TREAT[+event][+pleasurable][+highly]

For an added treat, we got to spend two days on the island of Capri.
It was a real treat to see the whales breaching so close to our boat.
It was hardly a treat for our guests to stand in the rain for half an hour!
John wanted to take his parents on a Caribbean cruise as a treat. (could also be sense 3, if John pays for it)

WordNet 3.0 Sense Numbers: 2

Sense Number 3: paying for an entertainment bill

Commentary: TREAT[+action][+social][+pay][+bill][+entertainment]
NOTE: occurs with a preceding possessive modifier

Dinner is my treat tonight. (I'm paying for everyone)
We thought it was going to be Mary's treat but she asked the waiter for separate checks.
He insisted that the trip to Paris was going to be his treat, she would pay nothing.

WordNet 0.0 Sense Numbers: 1a