Despite his talent, the renowned musician struggled with addiction and was known to be an alcoholic.

alcoholic 是由名词 alcohol（酒精）加上后缀 -ic 构成的形容词，表示"与酒精有关的"或"由酒精引起的"。 在句中 alcoholic 用作名词，指"酗酒者"或"酒精成瘾者"，即长期过量饮酒并对酒精产生依赖的人。