Also 7 coetanity. [f. L. coætāne-us (see next) + -ITY.] The quality of being coetaneous; contemporaneousness.
1622–62. Heylin, Cosmogr. (1674), Introd. 17/2. Borrowing … from Chronologies consent of time and co-etanity of Princes.
1799. Kirwan, Geol. Ess., 366. The hypothesis of the coetaneity of the marine and vitriolic acids.
