He became an alcoholic when his wife left him.

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"酒精的"。作为名词时，指"酗酒者"或"酒精成瘾的人"。 在句中 alcoholic 用作名词，指因过度饮酒而依赖酒精的人。