Pot
Pot is a slang term for cannabis that gained popularity in the 1930s. Shortened from the name of a Spanish grief potion, pot is an abbreviation of “potación de guaya.” This libation was created by soaking cannabis leaves in wine or brandy.
“She went on an errand to replenish her pot supply.”
“For dessert, we made chocolatey pot brownies.”
History of pot
Pot first appeared in this context in 1938 when African-American writer Chester Himes used the term in his short story “The Way We Live Now”:
“She made him smoke pot, and when he got jagged [high]… she put him on the street.”
Difference between pot and cannabis
There is no difference between pot and cannabis. “Cannabis” is often considered a formal term, whereas “pot” is more casual.