1540s, "pertaining to the two great arteries of the neck," from Greek karotides "great arteries of the neck," plural of karotis, from karoun "plunge into sleep or stupor," because compression of these arteries was believed to cause unconsciousness (Galen). But if this is folk etymology, the Greek word could be from kara "head," related to kranion "skull, upper part of the head," from PIE root *ker- "horn, head" (see horn (n.)).
carotid artery n.
An artery that originates on the right from the brachiocephalic artery and on the left from the aortic arch, runs upward into the neck and divides opposite the upper border of the thyroid cartilage, with the external and internal carotid arteries as its terminal branches; common carotid artery.
An artery with its origin in the common carotid artery, with branches to the superior thyroid, lingual, facial, occipital, posterior auricular, and ascending pharyngeal arteries, and with the maxillary and superficial temporal arteries as its terminal branches; external carotid artery.
An artery that arises from the common carotid artery opposite the upper border of the thyroid cartilage and terminates in the middle cranial fossa by dividing into the anterior and the middle cerebral arteries; internal carotid artery.
carotid ca·rot·id (kə-rŏt'ĭd)
Either of two major arteries, one on each side of the neck, that carry blood to the head. adj.
Relating to either of these arteries.