What does redirect exam testimony mean?

When a witness is called to the stand in a trial - the replies he gives to the first round of questioning he undergoes is called his direct testimony. When the opposing attorney gets to ask him questions he is said to be cross-examining him. Then, if the cross-examination raised some new questions in the first attorney's mind he might question him a second time - this is known as giving re-direct testimony. Then - if the opposing attorney follows up with more of his own questions he is said to be re-cross-examining.