: a conditioning exercise performed from a supine position by raising the torso to a sitting position and returning to the original position without using the arms or lifting the feet
The first known use of sit-up was in the 13th century
sit upADVERB➤abruptly, quickly, suddenly突然坐起來➤immediately立即坐直➤slowly慢慢坐起身◇She slowly sat up and looked around.她慢慢坐起來環顧四周。➤straight坐正PHRASES➤sit up and take notice (figurative) 關注起來;警覺起來◇Their actions have forced us to sit up and take notice.他們的行為迫使我們警覺起來。