A philosophical or general outlook that expects the worst outcome. Often contrasted with 楽観主義 (optimism).
His pessimism is affecting the people around him.
When you fall into pessimism, you can't get anything done.
Optimism; the direct opposite of 悲観主義.
Pessimistic (na-adjective); describes a pessimistic attitude or view, while 悲観主義 is the abstract concept or doctrine.
Compound of 悲観 (pessimistic view) + 主義 (principle, -ism). 悲観 is itself a Sino-Japanese word composed of 悲 (sad, mourn) and 観 (view, outlook).