Clockwise

A clockwise motion means 'like the clock's hands': from the top to the right, then down and then to the left, and back to the top. Or, when applied to a surface ("The Mexican wave usually runs clockwise") means that sequence will be: front, right, back, left, and all over again.

The question is: and why do all clocks run clockwise? Why that sense of rotation and not the other one?

The answer seems to be the clock's predecessor: the sundial. Clocks were first built in the North Hemisphere, and they were made to work like sundials. In order for the sundial to work (in the North), it must be placed looking Southward. Then, when the Sun moves in the sky (East to South to West), the shadow cast by the sundial moves in the opposite direction, that is West to North to East. That's why hours were drawn in sundials in that manner, and that's why modern clocks have their numbers set in the same way.

See Counterclockwise