Marked by imprecision and vacillation; inconstant; uncertain: The wishy-washy player keeps putting off the evil day/ It's not overpowering like Opium and not wishy-washy [1873+; fr a rhythmic reduplication of washy, ''weak, diluted, watered-down,'' probably influenced by wishy as suggesting vacillating desires; the original sense was ''weak, insubstantial, trashy,'' found by 1703]
Medical Definition of avidity. : a characteristic of antibodies (such as antitoxins) that tends to enhance their rate or stability in binding with an antigen Antibody avidity is an average measure of the affinity of the antibodies for a particular antigen in a serum sample.âDominic F. Kelly, The New England Journal of Medicine, 21 Dec. 2005.
Antibody Avidity and HIV Testing. The reason that avidity tests can be used to determine the length of an HIV infection is that over time, the avidity of the anti-HIV antibodies made by the immune system will improve. This method, however, is limited by prompt, effective treatment.