This is how you sign Basement in American Sign Language.

How to sign

To sign "Basement" in American Sign Language (ASL), with a closed fist and thumb up, rotate your hand underneath the flat hand of the other hand, which is facing down.

To sign "Basement" in American Sign Language (ASL), make a closed fist with your thumb pointing up and draw a circle by rotating it beneath your flat hand, which is facing down.