Depending on the year, the direction of the race can vary.

Over time, the direction of the polar jets would vary due to precession.

The direction which represents "on" also varies by country.

How does the direction of gravity vary with that?

The directions provided can vary from the creative (I even found a slightly faster way home) to the weird.

Both cells will see movement to the right but the direction seen will vary by 90 degrees.

The direction of the watch's eye had varied little as he walked along the road.

The shape, angle and direction of an erection varies considerably in humans.

The scope and direction of the imaginative excursion may vary very greatly.

The direction of the writing varies greatly in different places and times.