The Jewish Virtual Library states this:
The biblical betulah (בתולה) usually rendered "virgin," is in fact an ambiguous term which in nonlegal contexts may denote an age of life rather than a physical state. Cognate Akkadian batultu (masculine, batūlu) and Ugaritic btlt refer to "an adolescent, nubile, girl." That the woman who is so called need not necessarily be a virgo intacta is shown by the graphic account in a Ugaritic myth of the sexual relations of Baal with the goddess Anath, who bears the honorific epithet btlt (see Pritchard, Texts, 142). Moreover, in an Aramaic incantation text from Nippur there is a reference to a betulta ʾ (בתולתא) who is "pregnant but cannot bear" (Montgomery, in bibl. 13:9, p. 178). The male counterpart to betulah in the Bible is often baḥur (בָּחוּר), "young man," e.g., Jeremiah 31:12  and Amos 8:13 (cf. Joel 1:8, where a betulah moans for her bridegroom); and the word betulah interchanges with the somewhat synonymous age term ʿ almah (עַלְמָה), which also describes a young woman. Thus, in Genesis 24:16, 43, Rebekah is first called a betulah and then an ʿ almah. (Exactly the same interchange of the two words appears in a Ugaritic text.) ʿ Almah, despite a two-millennium misunderstanding of Isaiah 7:14, "Behold a young woman [LXX:παρθένοσ, "virgin"] shall conceive and bear a son," indicates nothing concerning the chastity of the woman in question. The only way that the term "virgin" can be unambiguously expressed is in the negative: thus, Sumerian and Akkadian, "undeflowered," and Akkadian, "not experienced," "unopened," and "who has not known a male." The description of Rebekah (Gen. 24:16), who is first called a betulah, "young woman," and then "whom no man had known" (cf. Judg. 21:12), is similar. In legal contexts, however, betulah denotes a virgin in the strict sense (as does batultu in certain Akkadian legal contexts).
What does Betulah mean? IS the Jewish Virtual Library even ran by Jews?