A destroyer is a strong and powerful ship that's part of a navy. It's designed to sink or damage enemy ships.
You might hear about destroyers on the news when there are conflicts at sea, but they're also often used for other tasks like rescuing people in trouble or helping with ocean research projects.
How common is "destroyer"?
Word destroyer is considered rare in modern English. It has a balanced usage among all categories: speech, fiction, newspapers and academic texts.
Definitions
noun
That which destroys something.
(military, nautical, historical) A small, fast warship with light gun armament, smaller than a cruiser, but bigger than a frigate.
(military, nautical) A larger warship with guided missile armament, usually intended for air defence or anti-ship roles. Often, but not always, larger than a frigate and smaller than a cruiser.