noun Astronomy.
  1. the point at which a heavenly body orbiting around a primary other than the earth or sun is closest to the primary.
Compare apocenter.

Origin of pericenter

First recorded in 1900–05; peri- + center
Related formsper·i·cen·tral, per·i·cen·tric, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018