Anagignoskomena is basically the Greek (and Orthodox Christian) term for what in Protestantism is called the Apocrypha and in Catholicism the Deuterocanonical books. It means “books worthy to be read” or “the readable books.” These include books of the Bible that were in the 1611 King James Bible but have since been removed from most Protestant Bibles, including the King James Bible you likely encounter at bookstores and online. Catholic Bibles still retain these books but in the middle between the Old and New Testament. In the Orthodox Old Testament, from the Greek Septuagint, they are in their appropriate places among the historical, wisdom, and prophetical books, although generally not used liturgically in Church but appropriate for study and home reading.
In the West, tending to follow the later Masoretic Hebrew text, the Apocrypha/Deuterocanon texts mainly were seen as from Greek and later texts, thus not part of the main Old Testament canon, following Judaism. However, recent scholarship such as the discovery of the Dead Sea Scrolls has supported the antiquity of the Septuagint Greek Old Testament, which survives in older forms than the Masoretic Hebrew.
The Orthodox Synod of Jerusalem in 1672 highlighted the Septuagint as canonical including the readable books,
“The Wisdom of Solomon,” “Judith,” “Tobit,” “The History of the Dragon” [Bel and the Dragon], “The History of Susanna,” “The Maccabees,” and “The Wisdom of Sirach.” For we judge these also to be with the other genuine Books of Divine Scripture genuine parts of Scripture. For ancient custom, or rather the [Orthodox] Catholic Church, which has delivered to us as genuine the Sacred Gospels and the other Books of Scripture, has undoubtedly delivered these also as parts of Scripture, and the denial of these is the rejection of those. And if, perhaps, it seems that not always have all of these been considered on the same level as the others, yet nevertheless these also have been counted and reckoned with the rest of Scripture, both by Synods and by many of the most ancient and eminent Theologians of the Universal Church. All of these we also judge to be Canonical Books, and confess them to be Sacred Scripture.
Psalm 151 is also included in the Septuagint Old Testament in Orthodox Bibles.
Sometimes 4 Maccabees and/or II Esdras also is included in Orthodox Bibles as an appendix.
“The Bible” as a definitive book has been less emphasized in Orthodoxy, which does not have a sense of “sola scriptura” like Protestantism or as much of a Scholastic approach historically to text as Catholicism. In English, “Holy Scriptures” is a more Orthodox-like phrase, and while there is a canon as indicated above (with the few appended variations in different Orthodox local Church cultures and languages), the Scriptures in Orthodoxy are viewed more as an organic whole interwoven with Church Tradition and liturgical tradition, illuminated by the holiness of the Church and her saints and by the Holy Spirit of Pentecost, rather than a confined revealed book standing on its own. So Scriptures are always to be read with prayers and with guidance from the Church Fathers and holy elders and liturgical use.
May the Lord give us good wisdom!