pessimism

n. act of seeing only the bad side of situations, tendency to expect the worst

Pessimism, from the Latin pessimus (worst), denotes a belief that the experienced world is the worst possible. It describes a general belief that things are bad, and tend to become worse; or that looks to the eventual triumph of evil over good; it is the antonym of optimism, the contrary belief in the goodness and betterment of things generally. A common conundrum illustrates optimism versus pessimism with the question - does one regard a given glass of water as: "Is the glass half empty or half full?" Conventional wisdom expects optimists to reply with half full and pessimists to respond with half empty, but this is not always the case.
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Negativism /neg·a·tiv·ism/ opposition to suggestion or advice; behavior opposite to that appropriate to a specific situation or against the wishes [more]Pessimism - Community and Resources

Noun
1. the feeling that things will turn out badly
(antonym) optimism
(hypernym) despair
(hyponym) cynicism
2. a general disposition to look on the dark side and to expect the worst in all things
(antonym) optimism
(hypernym) disposition, temperament

(n.)
The opinion or doctrine that everything in nature is ordered for or tends to the worst, or that the world is wholly evil; -- opposed to optimism.
  

(n.)
A disposition to take the least hopeful view of things.