POSSLQ

Noun

 * 1) * c. 1981,
 * You live with me, and I with you / And you will be my POSSLQ / I’ll be your friend and so much more / That’s what a POSSLQ is for.
 * You live with me, and I with you / And you will be my POSSLQ / I’ll be your friend and so much more / That’s what a POSSLQ is for.

Usage notes
The word POSSLQ entered American popular culture during the 1980s, but use outside the census context declined as unmarried cohabitation became more common and unremarkable and as the term "person of the opposite sex" excluded same-sex couples.