Polar Orbiting Environmental Satellite. A satellite which has a polar orbit, such as the NOAA series or Defense Meteorological Satellite Program systems.
Sort of like "cunt", but used more flexibly. Can also be used like "fuck". Or simply to mean "very" as in "poes poor", meaning "very poor". Also used in the local phrase, "Jou ma se poes" meaning "your mother's poes."