See first quotes from Raymond A. Palmer
aerocar n. | 1950 | Justice of Martin Brand in Other Worlds July 128/1 In the dark, a transfer was made to an aerocar, which took off immediately on a course directly over the Venusian jungles.
off-trail adj. | 1947 | Observatory in Amazing Stories Oct. 7/2 Don Wilcox gives us โThe Kettle In The Pitโ as one of his โoff-trailโ offerings.
space patrolman n. | 1939 | Phantom Enemy in Amazing Stories Feb. 103/2 The uniformed figure of a space patrolman rose from below and stepped into the control room.
superscientific adj. | 1947 | Observatory in Amazing Stories Oct. 6/2 The existence of strange, super-scientific ships in the atmosphere of earth!