n An unsteadymovement of the body in walking or standing, as if one were about to fall; a reeling motion; vertigo; -- often in the plural; as, the stagger of a drunken man.
v (transitive) Multiple groups doing the same thing in a uniform fashion, but starting at different, evenly-spaced, times or places (attested from 1856[http://www.etymonline.com/index.php?term=stagger Etymology] in :w:Online Etymology Dictionary | Online Etymology Dictionary).