To utilize means to use something, especially in a practical or effective way. When you utilize a dictionary to look up an unfamiliar word, you're putting that tool to work for a specific purpose. When a basketball coach utilizes her fastest players in the final minutes of a close game, she's making strategic use of their speed.

The word often appears in formal writing and speech, but it usually means the same thing as the simpler word “use.” Scientists might say they utilized a microscope in their research when they could just as easily say they used one. Sometimes people choose “utilize” because it sounds more official or important, but the clearer word is usually better.

That said, utilize can suggest putting something to work in a particularly clever or efficient way. When you utilize leftover materials from one project to build something new, you're being resourceful. When a chef utilizes every part of a vegetable, including stems and peels, she's using ingredients thoughtfully rather than wastefully.