ɔːˈθɒɡənəl ɔɹˈθɑɡənəl ɹɛkˈtæŋɡjəlɚ ɹɛkˈtæŋɡjʊlə having a set of mutually perpendicular axes; meeting at right angles wind and sea may displace the ship's center of gravity along three orthogonal axes a rectangular Cartesian coordinate system having four right angles a rectangular figure twice as long as it is wide