from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun A tendency to expect the best possible outcome or dwell on the most hopeful aspects of a situation.
  • noun The doctrine, asserted by Leibniz, that this world is the best of all possible worlds.
  • noun The belief that the universe is improving and that good will ultimately triumph over evil.

from The Century Dictionary.

  • noun In metaphysics: Properly, the metaphysical doctrine of Leibnitz that the existing universe is the best of all possible universes.
  • noun The doctrine that the universe advances on the whole, so as to be tending toward a state in the indefinite future different in its general character from that in the indefinite past.
  • noun The belief, or disposition to believe, that whatever exists is right and good, in some inscrutable way, in spite of all observations to the contrary.

from the GNU version of the Collaborative International Dictionary of English.

  • noun (Metaph.) The opinion or doctrine that everything in nature, being the work of God, is ordered for the best, or that the ordering of things in the universe is such as to produce the highest good.
  • noun A habitual tendency or a present disposition to take the most hopeful view of future events, and to expect a favorable outcome even when unfavorable outcomes are possible; -- opposed to pessimism.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun a tendency to expect the best, or at least, a favourable outcome
  • noun the doctrine that this world is the best of all possible worlds
  • noun the belief that good will eventually triumph over evil

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • noun the optimistic feeling that all is going to turn out well
  • noun a general disposition to expect the best in all things


from The American Heritage® Dictionary of the English Language, 4th Edition

[French optimisme, from New Latin optimum, the greatest good; see optimum.]


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  • WeirdNet is trying to be my psychiatric assessor. Definition four: 'your usual mood'.

    Apparently pessimism is also my usual mood...

    February 1, 2008

  • WeirdNet is trying to be all things to all people!

    I love the first definition too, where it practically uses the word to define itself!

    February 2, 2008

  • What cheek! I didn't know WeirdNet was so forward.

    February 2, 2008

  • The Days May Be Grim, but Here’s a Good Word to Put in Your Pocket (New York Times, November 19, 2009)

    “The Waterfalls” flowed in the East River. “The Gates” snaked through Central Park. Now New York’s latest large-scale public art project is being exhibited in an even unlikelier space: your wallet.

    On the back of seven million MetroCards distributed this fall is a single printed word: “optimism.” Composed in clean, bold, sans-serif letters, it floats in a sea of white just beneath the boilerplate fine print. Another seven million are on the way early next year.

    November 20, 2009