pessimist

Concise Oxford English Dictionary © 2008 Oxford University Press:
pessimism/ˈpesɪmɪzəm/

▶noun

• 1 lack of hope or confidence in the future.

• 2 Philosophy a belief that this world is as bad as it could be or that evil will ultimately prevail over good.

– derivatives
pessimist noun,
pessimistic adjective,
pessimistically adverb.

– origin C18: from L. pessimus ‘worst’, on the pattern of optimism.