Reply #11: "parthenos" means virgin who is not married...

[Viva_La_Revolution]

All unmarried women were assumed to be virgins...

The Septuagint, in Greek, is the oldest document we have from the Bible, from the third century before Christ, and always uses the word parthenos, who is a virgin not married.
The Hebrew Bible, the Masoretic Text, from the sixth century after Christ, uses two words for virgin: bethulah, about 60 times, who is an older virgin woman, and almah, who is a young virgin girl of a marriageable age. However, for Rebeccah, both words are used in different verses (Ge.24:16,43).
The Death See Scrolls, in Hebrew, from the third century before Christ, use the same words than the Masoretic Text.
In Isa.7:14 the word almah is used to give a sign of the birth of the Messiah: "The Lord himself shall give you a sign. Behold a virgin shall conceive and bear a son, and his name shall be called Emmanuel". God inspired Matthew to interpret Isaiah 7:14 for his day and ours in light of God's miraculous new work in Christ (Mt.1:23). Some Bibles translate in Isa.7:14 for "the young woman", or "girl", and it becomes a sign for nothing, if not properly explained, because we all were born from a "young woman". In fact, most Israelites were expecting the virgin birth of the Messiah centuries before the birth of Jesus Christ.
The word virgin is also used in a spiritual sense to refer to the nation (Isa.23:12,37:22, Jer.14:17). In other places the word is often translated maid or maiden, but the idea of chastity may still be involved (Ps.78:63, 148:12, Ezek.9:6).

edit: forgot the link
http://biblia.com/sex/virgin.htm