A spice used in Italian, Mexican, and Greek cuisine.
When dried, it can look similar to marijuana and is occasionally sold by dishonest dealers to nieve rookie pot smokers people who are trying to purchase weed but get screwed over with a bag of oregano instead, which is NOT marijuana.
Matt: "Dude. . .I just sold Jake a bag of oregano for $100"
a random act of douchebaggery; an arbitrary, pointless prank. originated from a myth where a group of tricksters would fill dime bags with scrunched-up oregano to imitate bags of weed, which they left at popular smoking spots. stoners finding the bags would soon cheer their good fortune and then lament their awful fortune upon realizing they had smoked a culinary herb.
douchebag: "mikhail just asked me to get him some coca cola, but i know he hates diet, and since the diet and regular varieties are visually indistinguishable, i will fill his cup with diet coke and watch him react in disgust when he drinks it!"
normal person: "you are such a child. grow up and stop pulling oregano pranks"