chronogram

[ kron-uh-gram ]

/ ˈkrɒn əˌgræm /

an inscription in which certain Roman numeral letters express a date or epoch on being added together by their values.

a record made by a chronograph.

Origin of chronogram

First recorded in 1615–25; chrono- + -gram¹

chron·o·gram·mat·ic

[kron-oh-gruh-mat-ik] /ˌkrɒn oʊ grəˈmæt ɪk/, chron·o·gram·mat·i·cal, adjective chron·o·gram·mat·i·cal·ly, adverb chron·o·gram·ma·tist, noun

There is another near relation of the anagrams and acrostics, which is commonly called a chronogram.

Essays and Tales |Joseph Addison
It might be supposed to be a chronogram, but for the introduction of the letter "E."

Notes and Queries, Vol. IV, Number 111, December 13, 1851 |Various
The date may sometimes occur as a chronogram, which should not be overlooked.

How to Catalogue a Library |Henry B. (Henry Benjamin) Wheatley
Webster defines a chronogram as an inscription, sentence, or phrase in which certain letters express a date or epoch.

Smithsonian Institution - United States National Museum - Bulletin 240 |Anonymous

Sometimes it is to be found at the end of the preface or dedication, and sometimes it is on the title-page as a chronogram.

How to Catalogue a Library |Henry B. (Henry Benjamin) Wheatley

chronogram

/ (ˈkrɒnəˌɡræm, ˈkrəʊnə-) /

a phrase or inscription in which letters such as M, C, X, L and V can be read as Roman numerals giving a date

a record kept by a chronograph

chronogrammatic (ˌkrɒnəʊɡrəˈmætɪk) or chronogrammatical, adjective chronogrammatically, adverb