[sit up] vi (13c) 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 "sat up late to watch the movie"
[sit up] vi (13c) 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 "sat up late to watch the movie"
Merriam-Webster English vocab. Английский словарь Merriam Webster. 2012