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

Eventually, Rebecca York told Stewart why her son did exactly 538 sit-ups every morning. —Luca Evans, Denver Post, 8 May 2026

That test had kids running sprints, doing push-ups and sit-ups, and completing other physical feats. —Claire Cameron, Scientific American, 6 May 2026

Verb

Occasionally, breakfast proceedings would be interrupted by a cheeky monkey sitting up on the rafters, and staffers would be on high alert with their wild gesticulating, causing tittering among diners. —Condé Nast, Condé Nast Traveler, 2 June 2026

This new vision of luxury remains firmly rooted in faultless service and astounding architectural design, but also weaves in a profound connection to place and the thrill of experiencing it just as the world is starting to sit up and take notice. —Lauren Keith, Robb Report, 30 May 2026

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