跶 is a rarely-used character that almost exclusively appears as a bound morpheme in colloquial disyllabic compounds. The most common are 蹦跶 (bèngda, to bounce or flounder, like a fish out of water) and 溜跶 (liūda, to take a leisurely stroll). It does not function as a standalone word, and the dictionary gloss 'to stumble' is likely a misattribution or confusion with another character.