Falter

verb
move hesitatingly, as if about to give way
Similar: waver
noun
the act of pausing uncertainly
“there was a hesitation in his speech”
Similar: hesitation, waver, faltering
verb
be unsure or weak
“Their enthusiasm is faltering”
Similar: waver
verb
walk unsteadily
“The drunk man stumbled about”
Similar: stumble, bumble