[n] a person who meddles in the affairs of others
nosey-parker, nosy-parker
a tale-bearing animal, backseat driver, butt in, butt-in, buttinsky, eavesdropper, fool, gossip, gossip columnist, gossiper, gossipmonger, horn in, informer, inquirer, inquisitive, inquisitor, interfere, interlope, intermeddler, kibitzer, make, meddler, m