disfluency
noun
dis·flu·en·cy dis-ˈflü-ən(t)-sē 
variants or dysfluency
1
: an involuntary disruption in the flow of speech that may occur during normal childhood development of spoken language or during normal adult speech but is most often symptomatic of a speech impairment
especially : a disorder of vocal communication that is marked by frequent involuntary disruption or blocking of speech (as by repetition of all or part of a word or by prolonging vocal sounds) and typically has an onset during childhood : stuttering
2
: an act or instance of disfluency : stutter
disfluent
dis-ˈflü-ənt
adjective or dysfluent
a disfluent child
dysfluent speech
Example Sentences
Recent Examples on the Web Google is constantly updating its Google Assistant with new voice samples to better understand people with accents or speech disfluencies. 
Kevin Wheeler, USA TODAY, 6 Jan. 2020 People who stutter experience an excessive amount of disfluency, or involuntary speech disruptions, stumbling over at least 10 percent of their words. Rachel Hoge, Washington Post, 5 Nov. 2017
Kevin Wheeler, USA TODAY, 6 Jan. 2020 People who stutter experience an excessive amount of disfluency, or involuntary speech disruptions, stumbling over at least 10 percent of their words. Rachel Hoge, Washington Post, 5 Nov. 2017 Word History
First Known Use
1961, in the meaning defined at sense 1
Medical Definition
disfluency
noun
dis·flu·en·cy
variants or dysfluency
(ˌ)dis-ˈflü-ən(t)-sē
plural disfluencies
1
: an involuntary disruption in the flow of speech that may occur during normal childhood development of spoken language or during normal adult speech but is most often symptomatic of a speech impairment
especially : a disorder of vocal communication that is marked by frequent involuntary disruption or blocking of speech (as by repetition of all or part of a word or by prolonging vocal sounds) and typically has an onset during childhood : stuttering
2
: an act or instance of disfluency : stutter