verb

• (intransitive) To carry oneself in a depressed, lackadaisical manner; to give oneself up to low spirits; to pout, sulk.
• (transitive) To make spiritless and stupid.

noun

• (archaic) A dull, spiritless person.
  "putting gulleries on some or other till they have made by their humouring or gulling ex stulto insanum, a mope or a noddy"
• (pornography industry) A bottom feeder who "mopes" around a pornography studio hoping for his big break and often does bit parts in exchange for room and board and meager pay.
  "2011: LA Weekly, documenting uses dating to the 1990s The porn industry is many things. Subtle is not one of them. So when Porn Inc. went searching for a job title for people like Stephen Hill, the choice was "mope." It's based on the off-camera life of these fringe actors, hangers-on who mope around the studios hoping for a bit role, which if they're lucky might bring them $50 plus food — and the chance to have sex with a real, live woman.https://web.archive.org/web/20110310155324/http://www.laweekly.com/2011-02-24/news/porn-machete-murder/"