To hem means to fold over the edge of fabric and sew it down to prevent fraying and create a neat finish. When your pants are too long, someone might hem them by cutting off the extra fabric, folding up the edge, and stitching it in place. Nearly every piece of clothing you wear has hems: at the bottom of your shirt, the cuffs of your sleeves, and the legs of your pants.

The word also describes being trapped or surrounded, usually in the phrase hemmed in. You might feel hemmed in if you're stuck in the middle of a crowded hallway with no way to move. A hiker could be hemmed in by thick brush on all sides. The connection makes sense: just as a hem encloses the edge of fabric, being hemmed in means something is closing around you, limiting your movement or options.

When someone hems and haws, they're hesitating and making uncertain sounds like “umm” and “well” instead of giving a clear answer. If your teacher asks whether you finished your homework and you start hemming and hawing, she'll know you're stalling because you don't want to admit you forgot.