oil switch[′ȯil ‚swich]
A switch whose contacts are immersed in oil in order to suppress the arc and prevent the contacts from being damaged.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
A switch which is immersed in a special insulating fluid, usually oil.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.