His lifestyle is very monastic, with only the bare essentials in his room.

monastic 来自名词 monastery（修道院），加上形容词后缀 -tic 构成。monastery 本身源自希腊语，表示"独居、隐居"的意思。 monastic 形容像修道院僧侣那样的生活方式，特点是极度简朴、清苦、克制，只保留最基本的生活必需品。