[ 'palɪə(ʊ)si:n , 'peɪ- ]
( US Paleocene )
■ adjective Geology relating to or denoting the earliest epoch of the Tertiary period (between the Cretaceous period and the Eocene epoch, about 65 to 56.5 million years ago), a time of rapid development of mammals.
Origin
C19: from palaeo- + Gk kainos 'new'.