To skim means to read something quickly, looking for the main ideas without reading every word carefully. When you skim a chapter before class, you might read the headings, the first sentence of each paragraph, and any words in bold, getting a sense of what it's about without absorbing all the details. Students often skim assigned reading to decide which parts need closer attention.

The word also means to remove something from the surface of a liquid. A cook might skim the foam off the top of soup with a spoon, or skim cream from fresh milk. When you skim a stone across a pond, it bounces along the water's surface instead of sinking.

You can also skim over a topic in conversation, meaning you touch on it briefly without going deep. If someone asks about your vacation and you just mention a few highlights, you're skimming over the experience rather than sharing everything that happened.

The key idea in all these uses is moving lightly across a surface, taking only what's on top, whether that's the main points of a text, foam from soup, or highlights from a story.