Wassermann n 1: German bacteriologist who developed a diagnostic test for syphilis (1866-1925) [syn: {Agust von Wassermann}] 2: a blood test to detect syphilis; a complement fixation test is used to detect antibodies to the syphilis organism treponema; a positive reaction indicates the presence of antibodies and therefore syphilis infection [syn: {Wassermann test}, {Wasserman reaction}]