a person who is addicted to an activity, habit, or substance

a drug addict.

to cause to become physiologically or psychologically dependent on an addictive substance, as alcohol or a narcotic.

to habituate or abandon (oneself) to something compulsively or obsessively

a writer addicted to the use of high-flown language; children addicted to video games.

noun

activity , often injurious aficionado , buff , devotee , enthusiast , fan , fanatic , fiend , follower , freak * , habitu , hound * , junkie * , nut , practitioner , zealotnotes:an edict is a formal or authoritative proclamation; an addict is someone who is physiologically dependent on a substance or someone who is a devoted supporter or fan , acidhead , aficionado , dependence , druggie , habituate , head , hophead , hound , house , junkie , mainliner , pothead , slave , user , zealot