Virgin
The word virgin has different levels of meaning, and must be understood in context.
The word virgin originated from Latin virginem (nominative virgo) meaning a "maiden, unwedded girl or woman," also an adjective, "fresh, unused." This corresponds with the common, basic use of the word virgin: someone who has not experienced sexual intercourse.
In esotericism, the word virgin has a deeper meaning: it retains the root meaning "fresh" as in "pure," yet has levels of application.
Those who practice sexual transmutation without fornication (orgasm) retain (or recover) their purity, since it is fornication (orgasm) that is "unclean." (See: What is Fornication?) Therefore, someone who is chaste, who is preserving and transmuting their sexual power, is retaining or restoring their virginity.
"Some mistaken and confused esoteric students wrongly object to these teachings and affirm that Pythagoras, Zoroaster, Jesus, and other initiates were celibate, never having been with a woman. In all of the temples of the mysteries, sacred vestals [priestesses] existed. The materialists, the disrespectful ones, ones with evil intentions, arbitrarily pretended to call them “sacred prostitutes.” Albeit, these vestals were initiated virgins, esoteric virgins, even when their bodies were not physiologically virginal." - Samael Aun Weor, Tarot and Kabbalah
Note that this is a spiritual and psychological viriginity: the state of the physical body is another matter. For instance, Devaki, the mother of Krishna, knew and practiced sexual transmutation (solar brahmacharya), and she also had multiple children, yet without fornication (orgasm). Because she maintained her sexual purity, she retained her virgin (pure) state. These mysteries are ignored by common people.
However, there is a way to preserve the virginity of the physical body even with sexual cooperation: Virgine Subintroductis.
"During the Middle Ages, many Gnostics practiced the Maithuna with Vestal Virgins, calling this marvelous practice Virgine Subintroductis (Sexual Magic). The Virgine Subintroductis with Vestal Virgins was formidable. It was practiced in the form of Karezza, so that the vestals retained their virginity. In this excellent practice, the man and the priestess lay on their sides, making sexual contact. The man introduced his phallus gradually, with extreme caution, between the vaginal labia and the hymen. With time the hymen became elastic, thus enabling deeper penetrations each time. Thus, this is how vestals never lost their virginity; they remained virgins for their entire life." - Samael Aun Weor
The word virgin is also an esoteric degree of initiation, equivilent to the well known title "buddha" ("awakened one").
“Religious people know that a Virgin named “Immaculate Conception” exists. Any mystic-illuminati perfectly knows that she lives in Eden working with the immaculate conceptions of the Holy Spirit. When a conception without the spilling of the seminal fluid is performed, it is done by the Holy Spirit. Such a conception is under the vigilance and direction of the “Immaculate Conception.” We announce that this said Virgin is not the Hebrew Mary. Indeed, the “Immaculate Conception” is a woman who attained the degree of Virgin. Many similar women exist, true living Buddhas who attained the Fifth Initiation. Let us remember the Virgin of the Sea (Mother of Jesus), and the eleven thousand Inca Virgins, the Virgins of the stars, the Virgin of the law, etc. All of those women are living Buddhas, women who attained the Fifth Initiation of Major Mysteries (true human beings). The most elevated degree for a woman is that of Virgin. The most elevated degree for a human is that of Christ. The Virgin who renounces Nirvana and reincarnates in order to work for humanity as a human being elevates herself to the degree of Christ.” - Samael Aun Weor, Aztec Christic Magic