trip, trip-up, stumble, misstep -- (an unintentional but embarrassing blunder; "he recited the whole poem without a single trip"; "he arranged his robes to avoid a trip-up later"; "confusion caused his unfortunate misstep")
Overview of verb stumble
The verb stumble has 4 senses
stumble, falter, bumble -- (walk unsteadily; "The drunk man stumbled about")
stumble, trip -- (miss a step and fall or nearly fall; "She stumbled over the tree root")
stumble, hit -- (encounter by chance; "I stumbled across a long-lost cousin last night in a restaurant")
stumble, slip up, trip up -- (make an error; "She slipped up and revealed the name")