Virgin

The Hebrew words betula and almah, often translated as “virgin” or “young woman”, are rather general in meaning. They refer to a young and usually unmarried woman. This may be a woman who has never yet slept with a man.

Virginity was not a precondition for marriage. Men could marry a widow or a prostitute. Different rules applied only to priests (Leviticus 21:7). A high priest was permitted only to marry a virgin from his own tribe (Leviticus 21:13-14).

The Greek word parthenos, “virgin”, does not occur often in the New Testament. Mary, the mother of Jesus, is called a virgin in Matthew 1:23. This is a quotation from Isaiah 7:14 in the Septuagint. Here the meaning is indeed that Mary had never slept with a man.
In other passages in the New Testament (Mark 6:1-16) it is said that Jesus had brothers and sisters. For that reason, some church traditions assume that these were half-brothers and half-sisters: they were indeed children of Joseph, but not of Mary. Another way of trying to solve the problem was to see the brothers and sisters as cousins.