Emaciated person, about to die from starvation.

Klepsydra [clepsidra] (Meyers Konversations-Lexikon). Water clock, used earlier for timekeeping of court speeches, like hour-glasses symbolic of life going by.

In the Polish and Yiddish languages, it also means an obituary. In the Ghetto, it was a common term for emaciated people looking like their own obituary (a living corpse). Their days were numbered, and the term meant sympathy. When such a poor blighter was recommended for a workshop, he certainly had to be rejected as a klepsydra. Because the multitude of the ghetto inhabitants was in terrible condition, it is easy to imagine how usual the term klepsydra was.