D defs.my
Entry 1 sense Webster, 1913

Interplanetary

/ĭnˌ-tẽrp-lăn'-ət-ĕrˌ-ē/ · In·ter·plan·et·a·ry · IPA /ˌɪntərplˈænətˌɛriː/
01 a. Between planets; as, interplanetary spaces; interplanetary travel.
  1. 1.
    Between planets; as, interplanetary spaces; interplanetary travel.