（船的）龙骨the long piece of wood or steel along the bottom of a ship, on which the frame is built, and which sometimes sticks out below the bottom and helps to keep it in a vertical position in the water
v.
1.
[i][t]
~ (sth) (over)
（使）倾覆，翻倒to fall over sideways; to make sth fall over sideways
