Most people here are using the term incorrectly. What the term actually means in fighting game parlance is when you do some attack that you don't know will hit, then you "confirm" that it hit the opponent before following up with a further sequence of attacks. Failing to hit confirm either results in a wasted combo opportunity (if the attack hit and you didn't follow up), or a potentially unsafe or wasteful blockstring (if the attack did not hit and you did the rest of the sequence anyway).
In this game what people are talking about are attacks that can lead into either big combos or supers. It's become something of a fad to describe these moves as cheap in the past few days, even though hit confirming is like the most basic building block of all fighting games. I can only assume it's some form of parody.
This guy knows his salt
Come on, slam! And welcome to the jam! Pokemon Black FC: 2366 1933 3349