Definition of: stammer

(stam′ər) v.t. & v.i.
To speak or utter with a halting articulation, commonly with nervous repetitions or prolongations of a sound or syllable, and involuntary pauses: to stammer an apology.
—noun A halting, defective utterance. [OE stamerian]
—stam′·mer·er noun Synonym: stutter. Stammer and stutter are virtually interchangeable in general use. Frequently, however, stammer is associated with nervousness, excitement, or embarrassment, while stutter is reserved by the speech therapists for a particular speech disorder of obscure origin.