neuron

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Any of the impulse-conducting cells that constitute the brain, spinal column, and nerves in vertebrates, consisting of a nucleated cell body with one or more dendrites and a single axon.
• noun A similar impulse-conducting cell in invertebrates.

from The Century Dictionary.

• noun The cerebrospinal axis in its entirety; the whole of the encephalon and myelon, or brain and spinal cord, considered as one.
• noun In entomology, a nervure of an insect's wing; a vein or costa.
• noun Same as neurone.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Anat.), obsolete The brain and spinal cord; the cerebro-spinal axis; myelencephalon.
• noun (Cell Biology) The characteristic specialized cell that is part of the nervous system, serving to conduct electrical impulses to and from the brain, and also between other parts of the body, and composed of a main cell body, the axon, with a varying number of processes of varying length, the dendrites; a nerve cell. The movement and behavior of higher animals depends on the signals tranmsitted by such nerve cells.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun cytology A cell of the nervous system, which conducts nerve impulses; consisting of an axon and several dendrites. Neurons are connected by synapses.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a cell that is specialized to conduct nerve impulses