Eustacia, the ancestor of mid-century fave Stacy, is just the kind of fusty old relic that might be polished up for modern use. Eustacia Vye is the central character of ThomasHardy's The Return of the Native.
Eustacia Vye, half-Corfiote beauty in ThomasHardy's novel 'The Return of the Native'
Eustacia Yewbeam, character in the Children of the RedKing series by Jenny Nimmo
Eustacia Andrapov, character in the NancyDrew computer game series
Eustachian tubes, part of the inner ear