Definition of space cadet
: a flaky, lightheaded, or forgetful person
Examples of space cadet in a sentence
Don't be such a space cadet.
Did You Know?
Space cadet has been used derogatorily since the late 1970s, but long before then it referred to the rank that the character Matt Dodson hoped to achieve in Robert Heinlein's 1948 novel Space Cadet. Other writers of futuristic fiction followed Heinlein's lead, using the word in reference to young astronauts. From there the meaning broadened to cover any space travel enthusiast. Today the word is occasionally used as a slang word for a pilot who shows off, but it most commonly refers to those of us who may seem to have our minds in outer space while our bodies remain earthbound.
First Known Use of space cadet
SPACE CADET Defined for English Language Learners
Definition of space cadet for English Language Learners
: a person who does not pay attention or who tends to forget things
Learn More about space cadet
Seen and Heard
What made you want to look up space cadet? Please tell us where you read or heard it (including the quote, if possible).