sit-up

1 of 2

noun

ˈsit-ˌəp 

: a conditioning exercise performed from a supine position by raising the torso to a sitting position and returning to the original position without using the arms or lifting the feet

sit up

2 of 2

verb

sat up; sitting up; sits up

intransitive verb

1

a

: to rise from a lying to a sitting position

b

: to sit with the back erect

2

: to show interest, alertness, or surprise

sit up and take notice

3

: to stay up after the usual time for going to bed

Examples of sit-up in a Sentence

Recent Examples on the Web

Noun

Started in the late 1950s by President Dwight Eisenhower, the fitness test evolved into five parts: curl-ups, a shuttle run, pull-ups or sit-ups, a sit-and-reach and a one-mile run. —Jessie Balmert, Cincinnati Enquirer, 10 June 2025

It is often touted as an abdominal exercise, serving as an alternative to traditional sit-ups and crunches. —Melissa Rudy, FOXNews.com, 17 June 2025

Verb

The boy was sitting up, smiling and holding his blue blanket. —Joshua Rothman, New Yorker, 14 July 2025

Sheets stayed on his back for a few minutes before sitting up and then quickly standing. —Jeff Sanders, San Diego Union-Tribune, 1 June 2025

Word History

First Known Use

Noun

1900, in the meaning defined above

Verb

13th century, in the meaning defined at sense 1a

Rhymes for sit-up

• backup
• blowup
• breakup
• buildup
• checkup
• cleanup
• holdup
• hookup
• lineup
• lockup
• makeup
• markup

Kids Definition

sit-up

noun

ˈsit-ˌəp

: an exercise done by lying on the back and rising up to a sitting position by bending forward at the waist without lifting the feet and returning to the original position