The Book of the Dead (Spells for Going Forth by Day)
Not one book but a personal toolkit of spells, copied fresh for each journey into the next world.
Also: Book of the Dead · Spells for Going Forth by Day · going forth by day · Totenbuch · funerary papyri · Book of Coming Forth by Day · BD
What scholars call the 'Book of the Dead' is the Egyptians' collection of 'Spells for Going Forth by Day': funerary texts written on papyrus (and coffins, amulets, and tomb walls) to help the dead navigate the afterlife — passing its dangers, answering its gatekeepers, and reaching the blessed realm. There was no single fixed book; each papyrus drew a different selection of spells, often illustrated with vignettes. It grew out of the earlier Pyramid and Coffin Texts.
In short
The modern name for a corpus of funerary spells — the Egyptians' 'Spells for Going Forth by Day' — copied on papyri and other media from the New Kingdom onward to guide, protect, and empower the deceased in the afterlife.
Where it’s found
The Book of the Dead (New Kingdom onward; e.g. the Papyrus of Ani, Dyn. 19)
How the idea developed across Egypt
Emerges in the New Kingdom (Dyn. 18) out of the Coffin Text tradition; selection and wording vary from papyrus to papyrus (no canonical text); a more standardized 'Saite recension' appears in the Late Period (Dyn. 26). The Bonn Totenbuch-Projekt is the standard modern reference.
There is no fixed 'Book of the Dead' text — it is a varying corpus of spells. Cite the specific papyrus and spell number. Avoid Budge's obsolete edition; use Faulkner / the Totenbuch-Projekt.