A term originally used to define high quality marijuana, since the term has increased in popularity, drug dealers now use it very loosely to increase the price of average bud. Many bustas who have not smoked enough weed to tell the difference between high and mid quality nuggets will be fooled into buying overpriced "headies" because they are led to believe it is good. If someone reps their weed for being headies, stay away from them.
Headies are the buds at the top of the cannabis plant. It doesn't matter what strain or how it was grown(hydroponically or organically, indoors or outdoors etc). Headies have more trichomes (resin glands)than the rest of the bud on the plant and therefore is the best bud that the plant can produce. However, you can get shitty headies if you have a shitty plant. :)
headies is probally one of the best grade u can get in the states! it is very good and it will have ur face numb and your hands tingling if you know who to buy from! so stop smoking schwag and beasters if u can get some HEADIES!
Can also refer to a particular type of Hand-Blown Glass smoking pipe. Usually one-of-a-kind, very intricate, and typically quite expensive.
(Other spellings: headdy, heddy...)