stumbleとは何ですか?To miss one's step in walking or running; trip and almost fall.To proceed unsteadily or falteringly; flounder. See Synonyms at blunder.To act or speak falteringly or clumsily.To make a mistake; blunder.To fall into evil ways; err.To come upon accidentally or unexpectedly: "The urge to wider voyages . . . caused men to stumble upon New America” ( Kenneth Cragg). To cause to stumble.The act of stumbling.A mistake or blunder.