in reference to the geological epoch preceding the Eocene, 1874, from French paléocène, coined 1874 by French paleobotanist Wilhelm Philippe Schimper from paleo- + Latinized form of Greek kainos "new" (see recent), on model of earlier Miocene, Eocene, etc. It is, thus, the "old new" age.
palaver
palazzo
pale
paleo-
paleobotany
Paleocene
paleoclimatology
paleogeomorphology
paleolithic
paleontologist
paleontology