bob

Think of a cork bobbing on the waves—that’s a vivid starting point. As a verb, it means a quick up-and-down motion: a head might bob with excitement, and a float can bob in water. But it is not just about movement. It can also refer to a short, blunt haircut, like the classic "bob" style from the 1920s. In British English, it can also be old-fashioned slang for a shilling; people may still say "a few bob," even though coins have changed.

This word is delightfully versatile, with senses tied to movement, appearance, and history. At its core, it means a quick up-and-down motion. Imagine a fishing float bobbing on water, or a child’s head bobbing along to music. As a verb it describes repeating that motion—"He bobbed his head in agreement."

However, it also has a stylish side. A "bob" is a classic haircut, usually short and blunt, often ending near the jawline. Beyond fashion, it appears in tool names: a "plumb-bob" is a small weight on a string used to find a perfectly vertical line.

And there’s even a historical side: in British English, "bob" was once common slang for a shilling (a unit that disappeared before decimalisation in 1971), and people still say "a few bob" for a small amount of money. Historically, "to bob" could also mean to bow briefly, or to cut an animal's tail short, which is where the word "bobtail" comes from.

So whether it's describing movement, a timeless hairstyle, or old British coins, "bob" is a word with surprising range—a little up and down, a little stylish, and a little bit historical!