Search Result for "ion engine":
Wordnet 3.0

NOUN (1)

1. a type of reaction-propulsion engine to propel rockets in space; a stream of positive ions is accelerated to a high velocity by an electric field; 



WordNet (r) 3.0 (2006):

ion engine
    n 1: a type of reaction-propulsion engine to propel rockets in
         space; a stream of positive ions is accelerated to a high
         velocity by an electric field