D defs.my
Entry 1 sense Webster, 1913

magnetosphere

· mag·net·o·sphere · IPA /mæɡˈni.təˌsfɪr/
01 n. the magnetic field of a planet; the volume around the planet in which charged particles are subject more to the planet's magnetic field tha…
  1. 1.
    the magnetic field of a planet; the volume around the planet in which charged particles are subject more to the planet's magnetic field than to the solar magnetic field.