Nouns

(n)hesitation, waver, falter, falteringthe act of pausing uncertainly“there was a hesitation in his speech”

Verbs

(v)falter, waverbe unsure or weak“Their enthusiasm is faltering”
(v)falter, wavermove hesitatingly, as if about to give way
(v)stumble, falter, bumblewalk unsteadily, tripping repeatedly“The drunk man stumbled about”
(v)bumble, stutter, stammer, falterspeak haltingly“The speaker faltered when he saw his opponent enter the room”