: an old-fashioned instrument that is like a ruler with a middle piece that slides back and forth and that is used to do calculations
What made you want to look up slide rule? Please tell us where you read or heard it (including the quote, if possible).
Take our visual vocab quiz
A quick quiz about stuff worth knowing
The commonly misspelled words quiz
The Vocab Quiz Game for iPhone & iPad
"Incredibly fun and addictive. And informative!" User Review, iTunes