Search Result for "heliopause": 
Wordnet 3.0

NOUN (1)

1. the boundary marking the edge of the sun's influence; the boundary (roughly 100 AU from the sun) between the interplanetary medium and the interstellar medium; where the solar wind from the sun and the radiation from other stars meet; 



WordNet (r) 3.0 (2006):

heliopause
    n 1: the boundary marking the edge of the sun's influence; the
         boundary (roughly 100 AU from the sun) between the
         interplanetary medium and the interstellar medium; where
         the solar wind from the sun and the radiation from other
         stars meet