noun. One that interferes with the affairs of others, often for selfish reasons; a meddler.

noun. One that intrudes in a place, situation, or activity.

noun. undefined

noun. One that trespasses on a trade monopoly, as by conducting unauthorized trade in an area designated to a chartered company.

noun. A ship or other vessel used in such trade.

noun. One who trades without license.

noun. One who interferes obtrusively or officiously; one who thrusts himself into a station to which he has no claim, or into affairs in which he has no interest.

noun. One who interlopes; one who unlawfully intrudes upon a property, a station, or an office; one who interferes wrongfully or officiously.

noun. An unlicensed or illegitimate trader.

noun. One who interferes, intrudes or gets involved where not welcome, particularly a self-interested intruder.

noun. someone who intrudes on the privacy or property of another without permission

"The Dads get off scott free, because hey they aren’t pregnant, it must be Mom’s fault this interloper is arriving."

entrant  persona non grata  unwelcome person  

alien  boarder  crasher  encroacher  gatecrasher  

adventurer  adventuress  bounder  cad  charlatan  

intrude