In one sense, an ounce is an inch, at least in so far as the names of both units derive from a Latin source meaning one twelfth, an inch being a twelfth of a foot, and a troy ounce being a twelfth of a pound. This Latin source—uncia—developed differently as it made its way though Old French and Germanic: in Old French uncia became unce, which English adopted as ounce in the fourteenth century; in Germanic uncia became ungkja, which evolved into the Old English ynce before being respelt as inch in the sixteenth century. The usual abbreviation of ounce—oz.—is unusual in so far as ounce is not spelt with a z; however, the Italian counterpart to ounce—ouza—is spelt with a z and it may be that this word is the source of the abbreviation. Alternatively, the z of oz. may originally have been what is called a terminal mark, that is, a symbol used by early printers to indicate that a word had been shortened. Thus, the original abbreviation for ounce may simply have been an o followed by the terminal mark z; in time, the function of the z was forgotten, but the abbreviation oz. persisted. The same process is responsible for the abbreviation viz, a short form of videlicet, literally meaning one is permitted to see but used by some authors to mean in other words. The original abbreviation of videlicet was vi, but with the addition of the terminal mark it became viz.