As an adverb mortally
is fatally; in such a way as to cause death.
As an adjective mortall is
an archaic spelling of mortal.
mortally
English
Adverb
(
en adverb)
Fatally; in such a way as to cause death.
(obsolete) As a mortal.
*1596 , (Edmund Spenser), The Faerie Queene , V.1:
*:And all the depth of rightfull doome was taught / By faire Astræa with great industrie, / Whilest here on earth she lived mortallie […].