Pediment and Underbelly

Pediment noun - A triangular gable between a horizontal entablature and a sloping roof.

Underbelly and pediment are semantically related in bottom topic. In some cases you can use "Underbelly" instead a noun "Pediment", when it comes to topics like foundation.

Underbelly noun - A social sphere that exists outside of the mainstream.

Pediment and underbelly are semantically related in bottom topic. You can use "Pediment" instead a noun "Underbelly", if it concerns topics such as foundation.