noun Astronomy.
  1. the boundary between the earth's magnetosphere and interplanetary space, about 40,000 miles (65,000 km) above the earth, marked by an abrupt decrease in the earth's magnetic induction.
  2. a similar feature of some other planet.

Origin of magnetopause

First recorded in 1960–65; magneto- + pause Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Word Origin and History for magnetopause

1963, from magneto- in magnetosphere + pause (n.).

Online Etymology Dictionary, © 2010 Douglas Harper