speech impediment in which a person misarticulates sibilants
A lisp is a speech problem, linked to the misarticulation of 's'-sounds. This results in unclear speech. In many languages, these sounds are difficult to pronounce. There is a difference between lisping children who are in the process of learning to speak, and lisping adults. In many cases, lisping is easy to treat using specialized therapy. Some characters (especially in cartoons) lisp for a comic effect.