lisp (v.) Look up lisp at
sometimes lipse, late 14c. alteration of wlisp, from late Old English awlyspian "to lisp, to pronounce 's' and 'z' imperfectly," from wlisp (adj.) "lisping," which is probably imitative (compare Middle Dutch, Old High German lispen, Danish læspe, Swedish läspa). General sense "speak imperfectly or childishly" is from 17c. Transitive sense from 1610s. Related: Lisped; lisping. Suggestive of effeminacy from 14c.
lisp (n.) Look up lisp at
"act or habit of lisping," 1620s, from lisp (v.).