SIT UP


Meaning of SIT UP in English

sit up phrasal verb ( see also ↑ sit )

1 . to be in a sitting position or get into a sitting position after you have been lying down:

He was sitting up in bed, reading his book.

She sat up and reached for her glass.

2 . sit somebody up to help someone to sit after they have been lying down

sit somebody up in/on etc

I’ll sit you up on the pillows and you’ll be nice and comfortable.

3 . to sit in a chair with your back straight:

Just sit up straight and stop slouching.

4 . to stay up very late:

Sometimes we just sit up and watch videos all night.

5 . sit up (and take notice) to suddenly start paying attention to someone, because they have done something surprising or impressive:

If Maria succeeded, then everyone would sit up and take notice.

Longman Dictionary of Contemporary English.      Longman - Словарь современного английского языка.