LWS it's definition is "Laughing with a snort", used as a brief acronym to denote such amusement that the person actually snorts with laughter. Coined by the phrase "Laughing out loud" (Lol). LWS is a more genuine reaction to a funny joke as Lol has become such an overused phrase.
Person 1: Why did the nurse creep quietly past the medicine cabinent?
Person 2: I don't know why?
Person 1: because she didn't want to wake up the sleeping pills!!!
person 2: LWS!!!!!!!!