A streak is a long stripe or mark on a surface which contrasts with the surface because it is a different colour.

If something streaks a surface, it makes long stripes or marks on the surface.

If someone has a streak of a particular type of behaviour, they sometimes behave in that way.

If something or someone streaks somewhere, they move there very quickly.

A winning streak or a lucky streak is a continuous series of successes, for example in gambling or sport. A losing streak or an unlucky streak is a series of failures or losses.