The word means: things hidden away

works, usually written, of unknown authorship or of doubtful origin.

The word was first applied to writings which were kept secret because they were the vehicles of esoteric knowledge considered too profound or too sacred to be disclosed to anyone other than the initiated.

 later applied to writings that were hidden not because of their divinity but because of their questionable value to the church.

In general use, the word has come to mean "false, spurious, bad, or heretical"