The Oxford Thesaurus An A-Z Dictionary of Synonyms - moribundadj.

1) dying, in extremis, at death's door, failing, fading, with one foot in the grave, half-dead, breathing one's last, expiring, on one's last legs, on one's deathbed: Apparently moribund for weeks, he suddenly revived when he saw her. 2) ending, declining, obsolescent, weak, on the way out, waning, on the wane, dying out; stagnating, stagnant: At the time, the Ottoman Empire was already moribund.