Arising from multiple, different clones.
Note: Polyclonal antibodies (pAbs) are antibodies that are secreted by different B cell lineages within the body. They are a collection of immunoglobulin molecules that react against a specific antigen, each identifying a different epitope.
Example: A typical antiserum obtained from a conventional immunization is polyclonal.
Source:
PAC, 2018, 90, 1121. 'Terminology of bioanalytical methods (IUPAC Recommendations 2018)' on page 1142 (https://doi.org/10.1515/pac-2016-1120)