Someone who has a stammer tends to stammer when they speak. A speech-therapist cured his stammer. to speak with a lot of pauses and repeated sounds, either because you have a speech problem, or because you are nervous, excited etc = stutter. a speech problem which makes someone speak with a lot of pauses and repeated sounds = stutter
If you stammer, you speak with difficulty, hesitating and repeating words or sounds. Five per cent of children stammer at some point `Forgive me,' I stammered People cursed and stammered apologies. + stammering stam·mer·ing Of all speech impediments stammering is probably the most embarrassing
To make involuntary stops in uttering syllables or words; to hesitate or falter in speaking; to speak with stops and diffivulty; to stutter