from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The point of a body's elliptical orbit about the system's centre of mass where the distance between the body and the centre of mass is at its minimum.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. (astronomy) the point in an orbit closest to the body being orbited
peri- + apsis (Wiktionary)