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.
2. a healthy capacity for vigorous activity. 3. (biology) a hypothetical force (not physical or chemical) once thought by Henri Bergson to cause the evolution and development of organisms. 4. the property of being able to survive and grow. Familiarity information: VITALITY used as a noun is uncommon.