An interloper literally "runs between" — from Dutch for runner — originally meaning a rogue trader who darted into ports controlled by monopoly companies like the East India Company.
A person who becomes involved in a situation where they are not wanted or do not belong; historically, an unauthorized trader who infringed on the monopoly of a chartered trading company.
From inter- (between, among) + -loper, from Dutch loper (runner, rover), from lopen (to run), from Proto-Germanic *hlaupan (to run, to leap). Originally a commercial term for unauthorized traders who ran between the ships and ports controlled by monopoly trading companies like the East India Company. Key roots: *hlaupan (Proto-Germanic: "to run, to leap").
The interloper was originally a very specific kind of criminal: a trader who violated the monopoly of chartered companies like the East India Company or the Muscovy Company by trading independently in their exclusive territories. The -loper element comes from Dutch lopen (to run), making an interloper literally someone who "runs between" — darting into trade routes and ports controlled by others. The word's cousin