de facto
n.— «One’s unmarried partner is referred to as the de facto husband or wife by some authorities. This has passed into Australian casual usage, in contrast to other English-speaking countries, as the slang term defacto to refer to one’s significant other. e.g. “This is my defacto, Rachael”. This is equivalent to the term common-law husband or wife in other countries of the British Commonwealth and in the U.S.» —“Options for “Marital status”” by Avlokana Åvlokana (Australia) Apr. 26, 2004. (source: Double-Tongued Dictionary)