屁股 (pì gu): ก้น

The child ran too fast in the park and accidentally fell; his buttocks landed right in a mud puddle, and his pants got completely dirty.

After sitting in the office all day, my buttocks have gone numb; now I have to stand up and move around slowly.

The baby ran around the living room with a bare bottom, and his mother chased him with a diaper, making everyone laugh.

He accidentally hit a rock while riding his bike, flew off the bike, and landed hard on his buttocks; the pain kept him from standing up for a long time.