adjective , noun
■ adjective [ only before noun ] ( informal )
1.
( of prices, etc. ) much lower than usual
SYN rock-bottom
2.
using a lot of force :
a knock-down punch
■ noun
1.
( in boxing ) an act of falling to the ground after being hit
2.
( in football ( soccer ) ) an act of hitting a high ball down to the ground or to another player