perish (v.)youdaoicibaDictYouDict
mid-13c., from periss- present participle stem of Old French perir "perish, be lost, be shipwrecked" (12c.), from Latin perire "to be lost, perish," literally "to go through," from per- "through, completely, to destruction" (see per) + ire "to go" (see ion). Related: Perished; perishing.
phthisis (n.)youdaoicibaDictYouDict
1520s, from Late Latin phthisis "consumption," from Greek phthisis "wasting, consumption; perishing, decay; waxing," from phthiein "to decay, waste away," from PIE root *dhgwhei- "to perish, die away" (cognates: Sanskrit ksitih "destruction," ksinati "perishes").