Folky/very soft music, sung almost always by a woman, usually about one's feelings. No electric guitars. Enya is textbook vaginamusic. As is Sarah McLachlan. Tori Amos occasionally produces such music.
"Do you want some music on?"
"Sure - what have you got?"
"Oh God. No. Just No. Anything but vaginamusic. Do you have any AC/DC?"