Why was "tantrum" trending last week?
late Old English awlyspian "to lisp," from wlisp (adj.) "lisping," probably of imitative origin (cf. Middle Dutch, Old High German lispen, Danish læspe, Swedish läspa). Related: Lisped; lisping.
1620s, from lisp (v.).
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.