change of direction: Occurs when a molinete or an ocho-like movement is stopped and sent back upon itself. Typical in club-style tango where many such brakes are used to avoid collisions. Describes a movement done on either foot, pivoting forward of backward, and going either left or right.
(from tejastango.com (http://www.tejastango.com/terminology.html#ocho))
Ocho Cortado is a mistake - really, the cut ocho is a cut turn ... a reverse of direction, because you go front, open, and then you go to the other side. It's not that you are cutting the ocho anywhere, it's just you are making a turn to one side and then you start to the other side. So you have a front step and an open step. That's what an ocho cortado is. (Fabián Salas)
(from tangocanberra.asn.au (http://www.tangocanberra.asn.au/words.htm#Ocho))