Blavatsky
Original sense
In her sevenfold constitution the astral body is the linga-śarīra: the model-body or design-body, a subtle double that is the mold of the physical form. It is born with the body, dies with it, and is not the vehicle of conscious travel after death. She warned that ‘astral body’ was used loosely for several different sheaths.
The Linga-Śarîra is the astral body, the phantom or double, the design-body that perishes with the physical.
She also spoke of kama-rupa (the desire-form that can persist after death) as an ‘astral soul,’ which later writers mixed with this. Besant and Leadbeater reassigned ‘astral body’ to the emotional body and renamed her linga-śarīra the ‘etheric double’ — a nomenclature New Age inherited.