Smugness is the feeling of being too pleased or satisfied with yourself or something you have done.
Smugness is usually not a good thing because it can make other people feel annoyed or upset.
Examples:
His smugness after winning the game was annoying.
She showed her smugness after getting the highest score.
The cat's smugness after catching the mouse was clear.
His smugness was so big, it almost filled the room.
The smugness on her face was like a big, happy balloon.
The smugness of the squirrel who found the most nuts was funny.