interloper

(ĭn'tər-lō'pər)

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

[INTER- + probably Middle Dutch lōper, runner (from lōpen, to run).]

WORD HISTORY   The word interloper has its origin in the time when England was embarking on the course that would lead to the British Empire. Interloper, first recorded around 1590 in connection with the Muscovy Company, the earliest major English trading company (chartered in 1555), was soon being used in connection with independent traders competing with the East India Company (chartered in 1600) as well. These companies were established as monopolies, and independent traders called interlopers were not welcome. The term is probably partly derived from Dutch, the language of one of the great trade rivals of the English at that time. The inter- is simply the prefix inter-, which English has borrowed from Latin, meaning "between, among." The element -loper is probably related to the same element in landloper, "vagabond," a word adopted from Dutch landloper, with the same sense and composed of land, "land," and loper, from lopen, "to run, leap." The word interloper came to be used in the extended sense "busybody" in the 17th century.