Как по Английски будет extradós

noun

The rear surface of the human body from the shoulders to the hips.

Примеры использования:

He lay on his back

adverb

In the opposite direction from the one that one is facing or travelling towards.

Примеры использования:

He moved back a pace

verb

Give financial, material, or moral support to.

Примеры использования:

He had a newspaper empire backing him

adjective

Of or at the back of something.

Примеры использования:

The back garden

The posterior part of a human (or animal) body

noun

The upper or outer curve of an arch.

Примеры использования:

The outer boundaries of a voussoir are the extrados.