Noah Webster
Lisp
LISP, verb intransitive
To speak with a particular articulation of the tongue and teeth, nearly as in pronouncing th. Lisping is particularly noticed in uttering th for s, as yeth for yes. It is most common in children.
I lisped in numbers, for the numbers came.
LISP, verb transitive To pronounce with a lisp; as, she lisped a few words.
LISP, noun The act of lisping, as in uttering an aspirated th for s.