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1. Geology archaeol denoting the late part or division of a period, system, formation, etc.
2. Maths (of a limit or bound) greater than or equal to one or more numbers or variables
3. Informal any tooth of the upper jaw
4. Slang any of various drugs having a stimulant or euphoric effect
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005
Pertaining to rocks or strata that normally overlie those of earlier formations of the same subdivision of rocks.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.