Garlic is called garlic because its name originates from Old English. The word "garlic" derives from "garlēac," which is a compound of "gar" (meaning spear) and "lēac" (meaning leek), effectively meaning "spear-shaped leek." This likely refers to the shape of the garlic plant's leaves or the individual cloves resembling small spears.
Essentially, our current word is a direct descendant of an Anglo-Saxon description of the plant's appearance.