Whirr is a term that describes a continuous, low, humming sound often associated with machinery or mechanical devices. It can be heard in various contexts, such as when a fan operates, a computer's hard drive spins, or a drone flies. The sound is typically smooth and can create a sense of background noise. In addition to its auditory meaning, "whirr" can also refer to the rapid movement of objects, like the wings of a bird or the blades of a helicopter. This action often produces a similar humming sound, contributing to the overall experience of motion and energy in the environment.