[n] an unintentional but embarrassing blunder; "he recited the whole poem without a single trip"; "confusion caused his unfortunate misstep"
[n] an unsteady uneven gait
[v] make an error
[v] miss a step and fall or nearly fall; "She stumbled over the tree root."
[v] walk unsteadily
[v] encounter by chance; "I stumbled across a long-lost cousin last night in a restaurant"
blunder, bumble, falter, hit, lurch, misstep, slip up, stagger, trip, trip, trip up