Canine is derived from the Latin word canis (dog) and caninus and from French.  It entered English in late Middle English.  

The earliest known use of the word canine is in the early 1600s. OED's earliest evidence for canine is from 1607, in the writing of Edward Topsell, Church of England clergyman and author. 

Canine teeth: The canine, also known as the cuspid, is a tooth located in all four quadrants of the mouth as the third tooth from the midline (central incisor > lateral incisor > canine). It is a sharp tooth with a single cusp, designed to tear or pierce food.  In real life, many animals use their canine teeth to fight off predators and mating rivals. However, humans have smaller canines than many of these animals. The size and shape of our canine teeth is one trait that we share with the group called hominins.

Just the facts:

Canine Definition & Meaning - Merriam-Webster