(1):

A hospital or ambulance service established as a result of, though not provided for by, the Geneva convention of 1864; any of the national societies for alleviating the sufferings of the sick and wounded war, also giving aid and relief during great calamities; also, a member or worker of such a society; - so called from the badge of neutrality; the Geneva cross.

(2):

The crusaders or the cause they represented.