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

At the time it was eliminated in 2012, the Presidential Fitness Test included a one-mile run, sit-ups, a shuttle run, a sit-and-reach test, and pull-ups or push-ups. —Nuria Martinez-Keel, Oklahoma Voice, 8 Jan. 2026

According to the outlet, Nelson regularly does sit-ups, arm rolls, leg lifts and jogs in place to keep his physical health in order. —Jack Irvin, PEOPLE, 22 Dec. 2025

Verb

One mom set up a full Mexican buffet, complete with a piñata—for a group of 6-month-olds who couldn't even sit up, let alone swing a stick. —Lauren Brown West-Rosenthal, Parents, 7 Jan. 2026

Aisha threw back the blanket and tried to sit up, but Olie raised a hand to stop her. —Literary Hub, 7 Jan. 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