streak / strēk/ • n. 1. a long, thin line or mark of a different substance or color from its surroundings: a streak of oil. ∎  Microbiology a narrow line of bacteria smeared on the surface of a solid culture medium.2. an element of a specified kind in someone's character: there's a streak of insanity in the family Lucy had a ruthless streak. ∎  a continuous period of specified success or luck: the theater is on a winning streak the team closed the season with an 11-game losing streak.• v. 1. [tr.] cover (a surface) with streaks: tears streaking her face, Cynthia looked up his beard was streaked with gray. ∎  dye (hair) with long, thin lines of a different, typically lighter color than one's natural hair color: [tr.] hair that was streaked blond. ∎  Microbiology smear (a needle, swab, etc.) over the surface of a solid culture medium to initiate a culture.2. [intr.] move very fast in a specified direction: the cat leaped free and streaked across the street.3. [intr.] inf. run naked in a public place so as to shock or amuse others.PHRASES: like a streak inf. very fast: he is off like a streak.streak of lightning a flash of lightning.DERIVATIVES: streak·er n. (in sense 3 of the verb ).

streak †mark, stroke OE.; thin line of different colour or substance from the rest XVI; stratum of coal or ore XVII; strip of land or water XVIII. OE. strica stroke of the pen, mark, line of motion, orbit, corr. to MLG., MDu. strēke (Du. streek), (O)HG. strich, Goth. striks, f. *strik- (see STRIKE).
Hence streak vb. †strike out XV; mark with streaks XVI.

streak The colour of a mineral when in the form of powder, which is usually produced by scratching the solid mineral on an unglazed porcelain plate (streak plate). The colour may be different from the mineral's colour in mass.

streak A general term for a virus disease in a (usually monocotyledonous) plant in which streaks of yellow colour or necrosis occur on the leaves.

streak A general term for a virus disease in a (usually monocotyledonous) plant in which streaks of yellow colour or necrosis occur on the leaves.