\E"o*cene\, a. [Gr. ? daybreak, dawn + ? new, recent.]
(Geol.)
Pertaining to the 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; as, Eocene deposits. -- n. The Eocene formation.
--Lyell.