informal housing
n.— «“So with a shortfall as big as that, is it any surprise that the prices have sky-rocketed and informal housing has grown beyond control?” he asks. Informal housing is estate agents’ parlance for slums, in which more than 60% of the city’s 18 million people live.» —“Mumbai houses priced out of market” by Monica Chadha in Mumbai, India BBC News Nov. 11, 2006. (source: Double-Tongued Dictionary)