glottochronology (n.)

word-forming element meaning "language," from Attic Greek glōtto-, from glōtta, variant of glōssa "tongue; language" (see gloss (n.2)).

1590s, "the science of time," from French chronologie or directly from Modern Latin chronologia; see chrono- + -logy. Related: Chronologer (1570s). Meaning "particular statement of the supposed order of certain past events" is from 1610s.