(1) Arranged in order or in a series. (2) Following in a series.
In writing the history of the revolution, he found it hard to put some of the events in sequential order.
Things in sequence, or regular order, are arranged sequentially. Most novels and films move sequentially, but some use techniques such as flashbacks that interrupt the movement forward in time. Sequential courses in college must be taken in the proper order, just as sequential tasks or steps must be done in order.