interloper

a person who meddles in the affairs of others summer residents were regarded as interlopers who had no deep commitment to the town's welfare Synonyms buttinsky (also buttinski), interferer, busybody, intermeddler, intruder, kibitzer (also kibbitzer), meddler, nosey parker [chiefly British]Related Words gaper, gawker, gawper [chiefly British], gazer, peeper, peeping Tom, prier (also pryer), rubberneck, rubbernecker, snoop, snooper, spy; blabber, discloser, gossip, gossiper, prattler, quidnunc, revealer, teller; betrayer, talebearer, tattler, tattletale, telltale; snake, sneak; informant, informer, snitcher, squealer, stool pigeon