de facto

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)