Joe Clark means in slang: 16th Prime Minister of Canada. He was Canada’s president for 10 months between 1979-1980. In the first election, he defeated Pierre Trudeau with Joe Clark winning the popular vote. He could’ve served for longer if he was better at managing, many say. He is also the youngest person to be inagurated the day before his 40th Birthday. (in Slang Dictionary, added by Umlaut)