Interstellar

Interstellar is a word made of two Latin words - inter, meaning 'between', and stellar, pertaining to stars. Interstellar simply means between, or among, stars. This is a bit too straightforward however, since Earth is clearly between the Sun and any other star. The Earth is not really in interstellar space however. Rather, we define a really very large region of space around each star which describes its region of influence, in terms of gravity, radiation, environment, etc. Interstellar space falls between all the distinct regions of influence of all the stars.