The navaja is a traditional Spanish folding-blade fighting and utility knife. One of the oldest folding knife patterns still in production, the first true navajas originated in the Andalusian region of southern Spain. In Spain, the term navaja is often used to generally describe all folding-blade knives. Design, origins, and development The etymology of the word navaja is derived from the Latin novacula, meaning razor, and the Andalusian knife known as the navaja is thought to have derived from the navaja de afeitar, or straight razor used for shaving. Like the straight razor, the navaja's blade folds into the handle when not in use. A popular slang term for the navaja in the 19th century was herramienta, which translates as "(iron) tool". While folding-blade knives existed in Spain even in pre-Roman times, the earliest Spanish knives recognizable as navajas date from around the late 1600s. The rise in popularity of the navaja occurred at a time of increased restrictions upon the wearing of swords and other bladed weapons by persons outside the Spanish nobility. Like the navaja de afeitar, the earliest navajas worked on the principle of the simple peasant's knife, with no backspring to hold the blade in place once opened. These early navajas were primarily designed as utility or work knives, and could easily be carried either openly or concealed on one's person. One of the more common early varieties of this type of knife was the navaja cortaplumas, used by clerical workers, draftsmen, and notaries to sharpen ink quill tips. With the development of reliable spring steel in Spain, the navaja could be fitted with a tempered steel, externally mounted backspring, making the design much more useful. The new spring-back navaja proved very popular throughout Spain and was later exported to or manufactured in other countries as well, particularly France and the island of Corsica. During the first part of the 18th century, the blade heel and backspring of the navaja were cleverly altered to provide a locking device for the blade. Pulling open the blade from the handle, the lock allowed the blade to rotate into the fully open position, where it locked into position. The locking mechanism itself consisted of pinion teeth (piñones or dientes) cut into the blade heel (talón de la hoja) that are engaged by a lug attached to either the backspring or a separate spring-loaded metal latch as the knife is