Why is the ninth month called September?
1727, "action of assorting according to quality," from French triage "a picking out, sorting," from Old French trier "to pick, cull" (see try). There seems to be some influence from or convergence with Latin tria "three" (e.g. triage for "coffee beans of the third or lowest quality"). In World War I, adopted for the sorting of wounded soldiers into three groups according to the severity of their injuries.
triage tri·age (trē-äzh', trē'äzh')
A process for sorting injured people into groups based on their need for or likely benefit from immediate medical treatment. Triage is used on the battlefield, at disaster sites, and in hospital emergency rooms when limited medical resources must be allocated.