A person who habitually sees the worst aspect of things or believes that the worst will happen. Somewhat formal or literary; in casual speech 悲観主義者 (ひかんしゅぎしゃ) is more common.
He is a born pessimist, always expecting the worst outcome.
Antonym meaning 'optimist'. 厭世家 is its direct opposite.
Compound of 厭世 (えんせい, 'pessimism; weariness of life') + 家 (か, 'person; specialist'). The exact historical derivation is uncertain, but the kanji 厭 carries a sense of 'dislike' or 'be tired of', and 世 means 'world' or 'society'.