ETYMOLOGY
from Latin coævus (of the same age),
from co- + ævum (age) + -ous
EXAMPLE
“… Finally, the Tetrad connects all Beings, of Elements, Numbers, Seasons of the Year, Coaevous Society; neither can we name any thing, which depends not on the Tetractys, as its Root and Principle: …”
From: The History of Philosophy: containing the lives, opinions, actions and discourses of the philosophers of every sect
By Thomas Stanley, 1660
Lexicophilia 