Unsystematic means done without a clear plan, order, or method. When your approach to something is unsystematic, you're working randomly or haphazardly rather than following an organized system.

Imagine searching for a lost library book by wandering around your house and checking random places as they occur to you: under your bed, then the kitchen counter, then back upstairs to your closet. That's unsystematic. A systematic search would mean checking one room completely before moving to the next, or thinking logically about where you last used the book.

Scientists work hard to avoid unsystematic research. If a biologist studying birds visits different forests at random times without recording conditions, her data becomes unreliable. She needs systematic observation: visiting the same locations at consistent times, recording weather and temperature, and following the same procedure each time.

The word often appears when someone critiques sloppy work. A teacher might say your note-taking is unsystematic if you jot down random facts without organizing them by topic. An unsystematic approach can waste time and produce poor results because you can't learn from patterns or avoid repeating the same mistakes.