falter

(noun) the act of pausing uncertainly. Synonyms: hesitation, waver, faltering. Example: "There was a hesitation in his speech."

(verb) be unsure or weak. Synonyms: waver. Example: "Their enthusiasm is faltering."

(verb) move hesitatingly, as if about to give way. Synonyms: waver.

(verb) walk unsteadily. Synonyms: stumble, bumble. Example: "The drunk man stumbled about."

(verb) speak haltingly. Synonyms: bumble, stutter, stammer. Example: "The speaker faltered when he saw his opponent enter the room."