(intransitive) To move gently and vertically, in either a single motion or repeatedly up and down, at or near the surface of a body of water, or similar medium.

(transitive) To cut (hair) into a bob haircut. / (transitive) To shorten by cutting; to dock; to crop. / To bobsleigh.

(Kenya, slang; UK and Australia, historical, dated) A shilling. / (Australia, dated slang) A 10-cent coin. / (slang) An unspecified amount of money.

A bobbing motion; a quick up and down movement. / A curtsy. / A bobber (buoyant fishing device). / Any of various hesperiid butterflies.

A bob haircut. / Any round object attached loosely to a flexible line, a rod, a body part etc., so that it may swing when hanging from it. / The dangling mass of a pendulum or plumb line.

A diminutive of the male given name Robert. / (cryptography, physics) The person or system receiving a message or signal from a source conventionally known as Alice.

A generic male person.

present participle of bob

The motion of something that bobs.

plural of bobbing