means The point in the orbit of the moon or a satellite where it comes closest to the Earth.

from From Greek 'perigeion,' built from 'peri-' meaning 'near' or 'around' and 'gaia/ge' meaning 'earth' — so literally 'near-Earth.' It traveled into English in the 1500s through the astronomy of the day, and shares its 'peri-' with cousins like 'perimeter' and 'period.' Its mirror-twin is 'apogee,' the moon's farthest, frostiest remove.