chronogram

Meanings

1. A sentence or inscription whose letters, when interpreted according to a system (such as Roman numerals) in which letters correspond to numeric values, stand for a particular date (usually the date of inscription) when rearranged.
2. A phylogenetic tree that has branch spans proportional to evolutionary time.

Etymology

From chrono- + -gram, from Ancient Greek χρόνος (khrónos, “time”) + γράμμα (grámma, “writing”).