Formal:
* Dysfluency: This is the most clinical and neutral term, referring to any interruption in the flow of speech.
* Stammering: This is a synonym for stuttering, often used in more formal settings.
* Disfluency: This is a more general term that refers to any interruption in the flow of speech, including pauses, repetitions, and hesitations.
Informal:
* Stuttering: This is the most common and straightforward term.
* Hesitation: This is a more general term that refers to a brief pause in speech.
* Block: This is a specific type of stuttering where the person is unable to produce any sound.
* Speech impediment: This is a general term for any difficulty with speech, including stuttering, lisping, and articulation problems.
Other options:
* Speech disfluency: This term is used in clinical settings to describe stuttering and other forms of disfluency.
* Speech disorder: This is a general term for any disorder that affects speech, including stuttering.
The best word to use will depend on the specific situation and the level of formality you are aiming for.