Definition reprinted with permission from Hood, Stephen B. (editor) available from Stuttering Foundation of America: [amazon 093338825X inline]
Fluent speech involves the ability to talk with normal levels of continuity, rate, rhythm, and effort. Fluency involves the smoothness with which units of speech (sounds, syllables, words, phrases) flow together. Fluent speech flows easily and is usually made without effort. Abnormally broken, slow, or effortful speech is not fluent.