1) A girl's name
. Not very common but still used.
2) A slang term to refer to heroin
. The term "Henrietta" comes from the fact that heroin also starts with an "H" and many other drugs
use girls' names as slang for their respective drug
Henrietta is sometimes used as a code word
for heroin when referring to the drug in a public setting or over the phone where one does not want to openly discuss illegal activities.
Henrietta is used like a person's name in such discussions. Like saying "When Henrietta is around I am always happy" to indicate that when heroin is readily available this person is always in a "happy" or euphoric