Cannabutter means: A product of cooking cannabis with butter, used to make edibles.. It is informal slang, fine in casual speech but not suited to formal contexts. It has drug-related associations; worth a calm conversation about which side of the topic your teen is on. This is a food-related word and harmless in itself. If your teen uses it, context will usually make the intent clear. A short, curious question about where they heard it is usually all that is needed to know whether to follow up.