Weed is only one of the names that marijuana can go by, it can also be called ganja, cannabis, pot, grass and other names. It can be called hemp or herb, loco weed, Jane, reefer, smoke, and nug.
Then there are other names that refer to weed, like Panama Red or Mexican Green, Indica and Sativa. When the weed is harvested and being smoked it can be referred to as a joint, a roach, kiff, Thai Sticks, spliff, dubby and puff.
There are some less common names for weed like Otis, Texas Tea, kabizzle, giggleweed, ganster, dry high, Buddha grass, gage, tea, and dope.
The name that is used for weed in some cases depends on the location, with weed being one of the common names for marijuana in the northern part of the U.S. and cannabis or grass is what weed is referred to in the southern U.S.