1. one of the small branches that extend from the barbs of a feather
Usage: biology

Examples

• The barbules on bird feathers hook together to create a smooth surface.
• Under the microscope, you can see the tiny barbules that give feathers their structure.
• When a feather gets ruffled, the barbules become separated and need to be smoothed back together.
• The intricate arrangement of barbules helps make feathers waterproof.
• Scientists study barbules to understand how feathers evolved for flight.