ungmö

Noun

 * 1) a woman who has never been married, especially one no longer (all that) young; a spinster
 * 2)  a young woman (without sexual experience), a damsel
 * 1)  a young woman (without sexual experience), a damsel

Usage notes
Only the first declension appears in Svenska Akademiens ordlista (SAOL), but the second one is fairly common due to being intuitive.