noun (n)

• periapsis in Earth orbit; the point in its orbit where a satellite is nearest to the Earth(noun.location)

  Antonym:
  apogee
  

  source: wordnet30
• That point in the orbit of the moon which is nearest to the earth; -- opposed to apogee. It is sometimes, but rarely, used of the nearest points of other orbits, as of a comet, a planet, etc. Called also epigee, epigeum.(noun)

  source: webster1913