Both Uses

relapse
in
Ligeia
(Auto-generated)

In a short period it was certain, however, that a relapse had taken place; the color disappeared from both eyelid and cheek, leaving a wanness even more than that of marble; the lips became doubly shrivelled and pinched up in the ghastly expression of death; a repulsive clamminess and coldness overspread rapidly the surface of the body; and all the usual rigorous illness immediately supervened.†
*

relapse = return to an undesirable previous condition
Why shall I pause to relate how, time after time, until near the period of the gray dawn, this hideous drama of revivification was repeated; how each terrific relapse was only into a sterner and apparently more irredeemable death; how each agony wore the aspect of a struggle with some invisible foe; and how each struggle was succeeded by I know not what of wild change in the personal appearance of the corpse?†

Definitions:

(1) (relapse)
to return to an undesirable previous condition -- especially illness, addiction, or bad behavior
(2) (meaning too rare to warrant focus)