Monkish is an adjective, not a person. It describes someone or something that feels like a monk’s life: quiet, strict, plain, and pulled back from ordinary pleasures. A monkish room might hold a bed, a chair, and almost nothing else. Monkish habits might mean eating little, going to bed early, and staying away from parties. It can be simply descriptive, but it often carries a small sting, as if the speaker finds that life too hard or too closed-off. It does not mean “a monk.” You cannot say “he is a monkish”; you say he seems monkish, or you talk about a monkish silence. Though actually, a real monk might not like the word — it is more a picture outsiders use than a title anyone claims.