Quantcast
Merriam-Webster Logo
  • Dictionary
  • Thesaurus
  • Scrabble
  • Spanish Central
  • Learner's Dictionary

sit up

intransitive verb

Definition of sit up

  1. 1a :  to rise from a lying to a sitting positionb :  to sit with the back erect

  2. 2 :  to show interest, alertness, or surprise <sit up and take notice>

  3. 3 :  to stay up after the usual time for going to bed



13th Century

First Known Use of sit up

13th century


Seen and Heard

What made you want to look up sit up? Please tell us where you read or heard it (including the quote, if possible).

WORD OF THE DAY

of striking ability or excellence

Get Word of the Day daily email!