| 1. | a speech defect consisting in pronouncing s and z like or nearly like the th-sounds of thin and this, respectively. |
| 2. | Phonetics. any unconventional articulation of the sibilants, as the pronunciation of s and z with the tongue between the teeth (lingual protrusion lisp), close to or touching the upper front teeth (dental lisp), or raised so that the breath is emitted laterally (lateral lisp). |
| 3. | the act, habit, or sound of lisping. |
| 4. | to pronounce or speak with a lisp. |
| 5. | to speak imperfectly, esp. in a childish manner. |

lisp (lĭsp)
n.
A speech defect or mannerism characterized by mispronunciation of the sounds (s) and (z) as (th) and (th). v. lisped, lisp·ing, lisps
To speak with a lisp.