phthisis \THAHY-sis, noun:

1. A wasting away.
2. Pulmonary tuberculosis; consumption.

At last Sister Hyacinthe began to speak of the immediate and complete cures of phthisis, and this was the triumph, the healing of that terrible disease which ravages humanity…
— Robert Hugh Benson, Lourdes

Apoplexy is no longer to be feared, but phthisis is there. Social phthisis is called misery.
— Victor Hugo, Les Misérables

Phthisis comes from the Greek root phthí which meant “to decay.”