A comb is a flat tool with a row of narrow teeth used to untangle and arrange hair. You pull a comb through your hair to smooth out knots and make it neat. Combs have been around for thousands of years: archaeologists have found ancient combs made from bone, wood, and ivory.

The word also describes similar objects with teeth or tooth-like parts. A rooster has a fleshy red comb on top of its head. Bees build honeycombs, structures with hexagonal cells that fit together like the teeth of a comb. When you comb through something, like combing through a book to find a specific passage, you're searching carefully and systematically, the way a comb moves methodically through each section of hair.

People use different kinds of combs for different purposes: wide-toothed combs for thick or curly hair, fine-toothed combs for straight hair or for checking for lice, and styling combs for creating specific hairstyles. A comb is simpler than a brush but often more precise, letting you work on small sections at a time.