What does axon mean?
An axon is the long, cable-like fiber of a neuron that carries electrical impulses away from the nerve cell's body and delivers them to other neurons, muscle fibers, or glands. It is one of the defining structures of nerve cells: where dendrites receive incoming signals, the axon transmits outgoing ones, often across considerable distances. Many axons are wrapped in a fatty insulating layer called the myelin sheath, which dramatically speeds signal conduction; damage to this covering, as in multiple sclerosis, impairs nervous function. The term belongs primarily to the vocabulary of neuroscience, anatomy, and medicine, appearing in research literature, textbooks, and clinical discussions of nerve injury and degeneration. Understanding the word matters because axons are fundamental to how brains and nerves communicate — every movement, sensation, and thought depends on signals traveling along them. Though strictly technical, 'axon' has become familiar to general readers through popular science writing about the brain and nervous system.
nounThe long, slender fiber of a neuron that conducts electrical impulses away from the nerve cell body toward other neurons, muscles, or glands.
- The long fiber of a nerve cell that carries electrical impulses away from the cell body to other cells.
"Each motor neuron sends its axon down the spinal cord to reach the muscle it controls."
"Damage to the myelin sheath slows the signals traveling along the axon."
"Under the microscope, each axon appeared as a delicate thread branching toward neighboring cells."
The standard plural follows regular English -s formation and appears frequently in anatomy and neuroscience contexts when referring to many nerve fibers.
"Microscopy revealed thousands of axons bundled together within the nerve."
A single axon can run over a meter long — the longest ones in your body stretch from the base of your spine all the way to your toes.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of axon
The word 'axon' derives directly from the ancient Greek 'axōn', meaning 'axis' or 'axle'. It was adopted into English anatomical usage in the nineteenth century as neuroanatomists established the structural components of the nerve cell, with the term standardized through the work of scientists describing neuronal morphology. Its transparent Greek origin also underlies derived terms such as 'axonometry', a drafting technique named for its use of measured axes rather than perspective.
How axon is actually used
A technical term used chiefly in anatomy, neuroscience, and medicine; rarely encountered outside scientific contexts.
Easily confused with axon
An axon is a nerve fiber in biology, while an axion is a hypothetical elementary particle proposed in physics.