In John Brunner's Stand on Zanzibar (1968), there is a slang term "shiggy," which refers to a transient woman who becomes a man's temporary romantic partner as a means to obtain shelter:
That would account for the development of the shiggy circuit, the fact that the world's big cities are alive with women who've never had a permanent home, but live out of a bag and sleep a night, a week, half a year wherever there's a man with an apartment to share.
I'm having trouble figuring out the origin of this term. Some of Brunner's invented slang has pretty clear etymology defined in-universe, e.g. "mucker" from "amok," but there's nothing within the book to suggest any words of similar sound or spelling that this term came from.
According to Urban Dictionary, "shiggy" is a term for obstacle-heavy off-trail terrain used by Hash House Harriers, but it's not clear if that term is as old as the novel, and that meaning doesn't really connect to the way Brunner uses it.
An old reference in Transactions of the Philological Society indicates that "shiggy" is an Irish term meaning "fairy", so maybe the ephemeral and fleeting nature of relationships with these women has led men to think of them as fairies. No real textual support for this, though.