- an exercise in which a person lies flat on the back, lifts the torso to a sitting position, and then lies flat again without changing the position of the legs: formerly done with the legs straight but now usually done with the knees bent.
Origin of sit-up
First recorded in 1835–45; noun use of verb phrase sit up
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for sit-up
It seemed as if the very rabbits must come and sit-up there, the jays and pigeons settle above; everything in all the wood gather.Tatterdemalion
Word Origin and History for sit-up
Online Etymology Dictionary, © 2010 Douglas Harper