a. (Zool.) Of or pertaining to the Oligochaeta. [ archaic ] Syn. -- oligochaetous. [ 1913 Webster ]
a. [ Oligo- + Gr. &unr_; new, recent. ] (Geol.) Of, pertaining to, or designating, certain strata which occupy an intermediate position between the Eocene and Miocene periods. -- n. The Oligocene period. See the Chart of Geology. [ 1913 Webster ]