Chronogram
Pronunciation : Chron"o*gram
Part of Speech : n.
Etymology : [Gr. chronogramme.]
Definition : 1. An inscription in which certain numeral letters, made to appear specially conspicuous, on being added together, express a particular date or epoch, as in the motto of a medal struck by Gustavus Adolphus in 1632: ChrIstVs DVX; ergo trIVMphVs. - the capitals of which give, when added as numerals, the sum 1632.
2. The record or inscription made by a chronograph.
Source : Webster's Unabridged Dictionary, 1913