to deprive (a woman) of her virginity; to ravish (her)
to spoil (something) or take away its beauty
They found a great deal of entertainment at the hotel, an enormous wooden structure, for the erection of which it seemed to them that the virgin forests of the West must have been terribly deflowered — Henry James
[Middle English deflouren via Frenchfrom Latin deflorare, from de- + flor-, flos flower]