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

For example, sit-ups to remove belly fat, or leg exercises to trim the thighs. —Bryant Stamford, The Courier-Journal, 29 Aug. 2025

Push-ups and sit-ups—these weight-bearing exercises are accessible and very functional. —Violeta Valdés, Vogue, 29 Aug. 2025

Verb

So Ronny sat up front while Cali dozed in the back, and the trio didn’t speak as the truck cut through the morning. —Bryan Washington, New Yorker, 7 Sep. 2025

Another factor for keeping the heat at bay was the distance from where an upper-level ridge pattern sits up for the summer. —Brayden Garcia, Fort Worth Star-Telegram, 2 Sep. 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