Apocrypha are writings or statements of doubtful authorship or authenticity. In Christianity, the word apocryphal (ἀπόκρυφος) was first applied to writings which were to be read privately rather than in the public context of church services—edifying Christian works which were not considered canonical Scripture. In the wake of the Protestant Reformation, the word apocrypha came to mean "false, spurious, bad, or heretical".
From a Protestant point of view, Biblical apocrypha are a set of texts included in the Septuagint and the Latin Vulgate, but not in the Hebrew Bible. While Catholic tradition considers some of these texts to be deuterocanonical, and the Orthodox Churches consider them all to be canonical, Protestants consider them apocryphal, that is, non-canonical books that are useful for instruction. Luther's Bible placed them in a separate section in between the Old Testament and New Testament called the Apocrypha, a convention followed by subsequent Protestant Bibles. Other non-canonical apocryphal texts are generally called pseudepigrapha, a term that means "false attribution".
The adjective "apocryphal" is often used to indicate that a writing on any topic is of doubtful authenticity; spurious, fictitious, false; fabulous, mythical.
The word's origin is the Medieval Latin adjective apocryphus (secret, or non-canonical) from the Greek adjective ἀπόκρυφος, apokryphos, (private) from the verb ἀποκρύπτειν, apokryptein (to hide away).
It comes from Greek and is formed from the combination of apo (away) and kryptein (hide or conceal).
The word apocrypha has undergone a major change in meaning throughout the centuries. The word apocrypha in its ancient Christian usage originally meant a text read in private, rather than in public church settings. In English, it later came to have a sense of the esoteric, suspicious, or heretical, largely because of the Protestant interpretation of the usefulness of non-canonical texts.