a clear liquid used, especially in the past, as an anaesthetic to make people sleep before a medical operation

Ether anaesthesia was introduced in 1846.

Police said he drugged her with ether and handcuffed her to a wall.

the sky or the air, especially considered as being full of radio waves

Mobile smartphones allow users to see each other as they talk over the ether.

A few years ago, we sent purchase orders through the mail rather than the ether of a computer network.