Sit up has 4 different meanings across 1 category:
Verb
Noun
1
Alternative spelling of sit-up; alternative spelling of situp
Verb
1
not go to bed
"Don't stay up so late--you have to go to work tomorrow"
"We sat up all night to watch the election"
2
change to an upright sitting position
"He sat up in bed"
3
To assume a sitting position from a position lying down.
Example Sentences
"Don't stay up so late--you have to go to work tomorrow"
verb
"We sat up all night to watch the election"
verb
"He sat up in bed"
verb
Broader Terms (hypernyms)