It is an incision made horizontally across the lower end of the uterus; this kind of incision is preferred for less bleeding and stronger healing

A transverse incision is one that crosses the main axis of the area being cut.

It means what it says that is, a transverse (horizontal) incision above the belly button

The success rate for vaginal birth after cesarean section in patients who have had a prior low transverse uterine incision is approximately 70%.

A vertical incision is called a transverse or Pfannenstiel incision depending upon the procedure.