Definition of: streak

(strēk) noun
1. A long, narrow, somewhat irregularly shaped mark, line, or stripe: a streak of lightning.
2. A not very marked characteristic; a vein; trace; dash: a streak of meanness; also, a transient mood; whim.
3. Mineral. The color of the line of powder left when a mineral is rubbed on an unglazed porcelain plate known as a streak plate.
4. A strake.
5. A layer or strip: meat with a streak of fat and a streak of lean.
6. Bacteriol. The application of an inoculum in a thin stripe, as across the surface of a culture.
7. Slang The act or an instance of streaking (v. def. 3).
—v.i.
1. To form a streak or streaks.
2. To move, run, or travel at great speed.
3. Slang To appear naked in a public place, usually briefly and especially while running, as for a thrill.
—v.t.
4. To mark with a streak; form streaks in or on.
5. Slang To appear naked in (a public place), usually briefly and especially while running, as for a thrill. [OE strica. Akin to STRIKE.]
—streaked adjective
—streak′er noun