1. As a character: Pangloss is a fictional character in Voltaire's satirical novel Candide. He is a philosopher who believes in optimism, claiming that "everything is for the best in this best of all possible worlds." This belief is, of course, deeply flawed and satirical, as the novel portrays a world riddled with suffering and injustice.
2. As a word: Panglossian is an adjective derived from the character. It refers to an excessively optimistic viewpoint, often ignoring or downplaying the negative aspects of reality. Someone who is panglossian is someone who always sees the bright side, even when it's not there.
In essence, "Pangloss" represents naive, often unrealistic optimism.