Behold, a virgin will be with child and bear a son, and she will call His name Immanuel.

 English: New American Standard Bible                    Greek OT: LXX

Isaiah 7

14.

"Therefore the Lord Himself will give you a sign: Behold, a virgin will be with child and bear a son, and she will call His name Immanuel.

δια τουτο δωσει κυριος αυτος υμιν σημειον ιδου η παρθενος εν γαστρι εξει και τεξεται υιον και καλεσεις το ονομα αυτου εμμανουηλ

Ever hear of the Parthenon? It was a temple to Athena, the Virgin (parthenos) - hence the name (appartments of the virgin/unmarried woman)! https://en.wikipedia.org/wiki/Parthenon#Etymology

Some Jews (and others) dispute that the Hebrew word here was virgin, rather than young girl. But clearly the 70 elders who translated the Septuagint agreed that it was virgin. And although the Hebrew came first, we really have no older versions of the Hebrew than the Greek (except for the Dead Sea Scrolls - and this passage is the same there). The Septuagint is the Bible quoted in the New Testament. And in context, God is promising a miracle as a sign. What is the miracle of a young girl having a child, if not a virgin? Here's a very informative article on this point: https://knowingscripture.com/articles/is-virgin-the-correct-translation-of-isaiah-7-14

 Matthew 1 Quotes the above verbatum, with the interpretation of Emmanuel added.

English: New American Standard Bible

Latin: Nova Vulgata

Greek NT: Textus Receptus (1550/1894)

English: King James Version

23.

"BEHOLD, THE VIRGIN SHALL BE WITH CHILD AND SHALL BEAR A SON, AND THEY SHALL CALL HIS NAME IMMANUEL," which translated means, "GOD WITH US."

“ Ecce, virgo in utero habebit et pariet filium, et vocabunt nomen eius Emmanuel ”, quod est interpretatum Nobiscum Deus.

ιδου η παρθενος εν γαστρι εξει και τεξεται υιον και καλεσουσιν το ονομα αυτου εμμανουηλ ο εστιν μεθερμηνευομενον μεθ ημων ο θεος

Behold, a virgin shall be with child, and shall bring forth a son, and they shall call his name Emmanuel, which being interpreted is, God with us.

BTW, an example (see the above article) of the Hebrew using a different word for virgin is Exodus 22:16 (originally 15). It is not different in the Greek (or Latin):

Si seduxerit quis virginem necdum desponsatam dormieritque cum ea, pretio acquiret eam sibi uxorem.

εαν δε απατηση τις παρθενον αμνηστευτον και κοιμηθη μετ' αυτης φερνη φερνιει αυτην αυτω γυναικα

And if a man entice a maid that is not betrothed, and lie with her, he shall surely endow her to be his wife.

Note that the ending παρθενον is the accusative case (object) whereas παρθενος is the nominative case (subject) - they are the same word. Same for the Latin virginem vs. virgo.