Definitionen
1.VerbTo assume a sitting position from a position lying down."Despite being cancer-ridden, Lorin sat up to greet the visitors."
2.VerbTo sit erect."Sit up straight, mister!"
3.VerbTo show sudden interest or surprise."He sat up when we mentioned the increased pay package."
4.VerbTo bounce, especially to a comfortable height.
5.VerbTo not go to bed (notionally remaining in a sitting position)."I sat up all night waiting for her to come home."
6.VerbFor a young lady to open her house for several successive nights for any visitors who wish to pay their respects.
7.NounAlternative spelling of sit-up.