Streaky describes something marked by irregular lines, stripes, or patches, or something that's inconsistent in quality or performance.

When you clean a window but leave streaks of soap or water behind, the glass looks streaky. Bacon is naturally streaky because it has alternating strips of fat and meat running through it. Your hair might look streaky if you've been out in the sun and some strands have lightened more than others.

The word also describes performance that goes up and down unpredictably. A streaky basketball player might score twenty points one game and only two the next. A streaky student might ace three tests in a row, then struggle on the fourth, then ace two more. Unlike someone who's consistently excellent or consistently struggling, a streaky performer is hard to predict.

In sports, you'll often hear about players being “hot” or “cold”: when they're hot, everything they try seems to work. When they're cold, nothing does. A streaky player lives in those extremes, brilliant one moment and off-target the next, rather than staying in a steady middle ground. The unpredictability is what makes someone or something genuinely streaky.