Limbs growing out from the trunk of a tree, or divisions of something larger like a business, government, or river.
From Old French branche, from Latin branca meaning 'paw' or 'claw,' possibly because branches reach out like animal paws. The metaphorical uses (business branches, government branches) developed over time.
Trees actually use branches to 'communicate'—through a network of fungi underground called the 'wood wide web,' trees share nutrients and warning chemicals through their roots, and scientists think they're essentially talking to each other about pest attacks.
Complete word intelligence in one call. Free tier — 50 lookups/day.