A fork of Rural Dictionary
Meow Meow is a nick name for Mephedrone which is actually plant food, but commonly bought online and used as a substitute for ecstasy.
Stores like www.plant-food.net sell this as plant food, yet it can be bought freely and used (wrongly so) as a drug.
Another nick name for the drug/plant food is "bubbles", this seems to be the street name for the substance in Scotland.
"You got any more Meow Meow?"
"Nah go and buy it online at www.plant-food.net rather than go through a dealer, it's legal, remember!"