1. A cartilaginous rod that runs along the back (dorsal) of all chordates () at some point in their life cycle.
2. A rod consisting of cartilage running underneath, and supporting, the nerve cord.
3. In embryology, a rod-shaped body of cells that is the center of development of the axis of the skeleton.
4. A flexible rodlike structure that forms the main support of the body in all chordates (animals having a notochord, or dorsal stiffening rod) during some stage of their development.

In vertebrates, the notochord develops into a true backbone in the embryonic phase while primitive chordates; such as, lancelets and tunicates, keep a notochord throughout their existence.

1. A derivative of the nervus intermedius (root of the facial nerve) which leaves the main nerve in the facial canal to enter the middle ear cavity.
2. A nerve given off from the facial nerve in the facial canal which passes through the posterior canaliculus of the chorda tympani into the tympanic cavity, crosses over the tympanic membrane and handle of the malleus, and passes out through the anterior canaliculus of the chorda tympani in the petrotympanic fissure to join the lingual branch of the mandibular nerve in the infratemporal fossa.

It conveys taste sensation from the anterior two-thirds of the tongue and carries parasympathetic preganglionic fibers to the submandibular ganglion, for innervation of the submandibular and sublingual salivary glands.