addict
https://gyazo.com/478e9b9525bf0e4092583e2352ef3919
source: [ゲーム中毒の女性｜無料GIF画像検索 GIFMAGAZINE 2904407]
noun
a person who is addicted to a particular substance, typically an illegal drug:
(麻薬などの)中毒者, 常用者, 依存者
e.g. a former heroin addict.
with modifier informal an enthusiastic devotee of a specified thing or activity:
｟くだけた話｠ (趣味･娯楽などに対する)熱狂的愛好者, 病みつきな人 (!通例中毒, 愛好対象を示す〖名詞〗の後で)
e.g. a self-confessed chocolate addict
e.g. a must-buy book for the crossword-puzzle addict.
ORIGIN
early 20th century: from the obsolete verb addict, which was a back-formation from addicted.