Definitions

1. noun

a person who uses or supplies illicit drugs

“The police were looking for the doper who sold the counterfeit pills.”

2. noun

a person who habitually uses performance-enhancing drugs

“The sports agency launched an investigation into the doper who cheated in the tournament.”

3. noun

a person who indulges in a particular habit or activity excessively

“The doper’s excessive drinking habits have become a concern for his family.”