Deutero-Isaiah (meaning "Second Isaiah") is a term that some scholars use for chapters 40–66 of the book of Isaiah. The word "deutero" comes from Greek and means "second." These scholars believe these chapters might have been written by a different author than chapters 1–39, though others disagree.
Deutero-Isaiah
From Tyndale Bible Dictionary, adapted by Mission Mutual. CC BY-SA 4.0.