A boaster is someone who is known for boasting—bragging, especially in a way that exaggerates or shows excessive pride about the boaster's skills, possessions, or accomplishments.

What does it mean to brag on someone?

To speak with pride on behalf of (someone else); to boast of the accomplishments of (someone else). I get very tired of parents who constantly brag on their children.

What do you mean by lethargic?

Lethargy causes you to feel sleepy or fatigued and sluggish. This sluggishness may be physical or mental. People with these symptoms are described as lethargic. Lethargy can be related to an underlying physical or mental condition.