with⋅draw⋅al
with-draw-uhl, with-drawl noun
1. The act or condition of withdrawing.
2. Pharmacology: the act or process of ceasing to use an addictive drug.
Yes, "junk" is slang for heroin, hence the term "junkie". A buddy of mine just got through Paroxetine withdrawal by smoking weed. It was the only thing that worked in the many times he tried.