swell

To swell is to expand or grow larger. If your brother's face started to swell after he ate lobster for the first time, you'd probably guess that he's allergic to shellfish.

You can use the word swell to describe what happens to an injured body part, like a black eye that swells up, or in a figurative way, to describe a feeling of fullness, like when your heart swells with pride at your sister's big music performance. In the 1930s, swell became a popular slang term meaning great or excellent. But it also can describe a wealthy, elegant person, like a group of swells at a fancy restaurant.