Laffy Daffy Posted in L Best definition Laffy Daffydrugs A phrase used to describe marijuana that makes you laugh uncontrollably for no reason. Person A- Laughing uncontrollably. Person B- Its that Laffy Daffy shit, son! How satisfied are you with the definition? Looking for Laffy Daffy meaning? Delighted that you discovered the greatest determine on our web site! Recently this definition was actually observed 3 times.