Definition of "interloper" []

• One that interferes with the affairs of others, often for selfish reasons; a meddler. (noun)
• One that intrudes in a place, situation, or activity: "When these interlopers choke out native species, ecologists see a danger signal” ( William K. Stevens). (noun)
• Archaic One that trespasses on a trade monopoly, as by conducting unauthorized trade in an area designated to a chartered company. (noun)
• Archaic A ship or other vessel used in such trade. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "The Dads get off scott free, because hey they aren’t pregnant, it must be Mom’s fault this interloper is arriving."
• "Way back in 2000, every single one came from Asimov’s, F&SF or Analog, save for an interloper from the semi-prozine Interzone."
• "This is especially the case if you have hard water and the interloper is a car parked in your favorite space along your lawn."