B1
a piece of underwear that covers the area between your waist and the top of your legs
Dictionary examples:
I forgot my underpants and had to buy new ones at work. So embarrassing! (0.0)
I put my underpants on backwards. No wonder everyone was laughing at me! (0.0)
I accidentally wore my underpants over my pants. I'm not a superhero! (0.0)
I need some new underpants. (41.8)