Rob & I were discussing the quality of my coffee w/a shot of Jack Daniels in it & joking how it was strictly 'medicinal'. Rob mispronounced medicinal (possibly a side-effect of drinking JD in coffee) & said it was 'medusinal'.
So he thought about it for a minute & said, "Marijuana is Medusinal. It gets you stoned."
Hence the new word:
Medusinal, adj.: possessing the quality of a narcotic, i.e. any substance that gets you stoned.
It can also be an adverb. Committing adultery in Muslim countries is Medusinal.