a space cadet

a space cadet

  (humorous)
a strange or crazy person I wouldn't trust him with the children - he's a real space cadet.
See Watch this space
See also: cadet, space
References in periodicals archive ?
New York, May 24 ( ANI ): A space cadet has shelled out 1 million dollars to bid for travelling with Leonardo DiCaprio on a Virgin Galactic trip to the moon.
The 'Titanic' star had put up the seat for auction in Cannes for nonprofit group amFAR that supports AIDS research and a space cadet has paid around 1 million dollars to bid at the auction that was served by Sharon Stone, chair of amFAR, New York Daily News reported.
High-ranking pilots are also high-value targets, since players earn more points for destroying a Star Lord than for a Space Cadet.