stumble in WordNet English dictionary

1. walk unsteadily
   "The drunk man stumbled about"
   stumble  falter  bumble 
   
2. encounter by chance
   "I stumbled across a long-lost cousin last night in a restaurant"
   stumble  hit 
   
3. make an error
   "She slipped up and revealed the name"
   stumble  slip up  trip up 
   
4. miss a step and fall or nearly fall
   "She stumbled over the tree root"
   stumble  trip 
   

1. an unsteady uneven gait
   lurch  stumble  stagger 
   
2. 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"
   trip  trip-up  stumble  misstep