Canine, aka the cuspid, the tooth between the lateral incisor and first bicuspid. It gets its name from canis, Latin for dog, which in turn comes from the Greek word for dog, kynos. The Greeks were indeed the first on record to note the tooth's superficial resemblance to the corresponding dog tooth, in particular the relatively long, often sharply pointed cusp.
The upper canines are sometimes called the "eye teeth", perhaps because their roots can extend close to the lower margin of the orbit during their development in the maxillary bones. For reasons unknown, the lower canines have been called the "stomach teeth", a phrase of uncertain origin that has all but disappeared.
Most dentists and dental hygienists freely use both canine and cuspid (perhaps preferring the former since canine would be a more familiar term to the majority of their patients). Among anatomists however the preferred term is cuspid (from the Latin cuspis, point); canine is not listed in the Terminologia Anatomica.
The crown of a developing canine (arrow) in the skull of a child approximately 9 years of age.
Photo by C Carpenter