Example:
He was boasting about his fly girlfriend.

Example:
Ted: I slept with Rebecca Stillworth and it was freaking amazing! We did it like eight times and I think I made her cum twice that cuz I'm so talented. Seriously, she even told me that they should make a statue of my penis.

James: I wish Ted would stop boasting about that.

Kevin: I know right? It happened like ten years ago.

Steve: You'd think he'd have something else to talk about by now.

Kyle: Dumbass.

*They all nod in agreement, except Ted who continues with his boasting, oblivious to his friends' disgruntlement*

Example:
The girls in school like to boast about being popular.

Example:
1. "Wait, Obama is president? You mean we finally got a black man as president? Boast!"

2. "That shit was boast when the guest performer came onstage."

Example:
Dude: Hey man thats some burnt toast

Brian Badonde: BOOOO Boast!!!

Example:
Here is a classic boast, replete with examples of jailhouse vernacular, entitled:

"Cipher's Boast"

Of myself, I freely admit, besides some small shit I ain't got no game

But I once knew this sly hustlin, fly dressin motherfucker who'd built himself quite a name

As quiet as its kept you may not know of the longshoe of the century

So let me deal out the holecard and put you wise to his pedigree

Cipher, from the street he attained kingpin status through concentration and kilos and pimpin hoes with big asses

He wore vines displaying taste well ahead of his time

And sharkskin kicks, bustin hoes in the ass who refused to turn tricks

But he always dealt solid to those in his flock and as much as it may come as a shock

He only layed out lames who tried to lay him two ways

You know some Lames just can't take the weight, but like a stone cold noble he did his bid and went straight!

Example:
Look at her with that new top she's being so boastful showing it of

Example:
Hey man, wanna get boasty?
Care to boast?
Hey man, got any boast?
That was some good shit. I'm boasty!

Example:
"Bouncer boasted that."