Synonyms for Terminally:

adv

fatally (adverb)
mortally, lethally, fatally.
lastly (adverb)
finally, lastly, completely.

adv.

fatally (adverb)
mortally, lethally, fatally.
lastly (adverb)
finally, lastly, completely.

Other synonyms:

adv.
lastly.
n.
fatally.