E'o-cēne1, a.
a. [Gr. ἠώς, day-break, dawn, and καινός, new, recent.] (Geol.) First in time of the three subdivisions into which the tertiary formation is divided by geologists, and alluding to the approximation in its life to that of the present era; pertaining to the eocene epoch; as, eocene deposits. Lyell.