Sway unsteadily, reel, or totter.

Doubt, waver, be shocked.

Have multiple groups doing the same thing in a uniform fashion, but starting at different, evenly-spaced, times or places (attested from 1856).

The motion of one who staggers.

That which staggers something or somebody.

In animation, the repetition of a sequence of frames to show struggling effort

Incredible, overwhelming, amazing.

“The army suffered a staggering defeat.”