rejoinder n. + Add to list US //ɹiˈdʒɔɪndɝ// re·join·der SynonymsEtymology Synonyms comebackcounterreplicationretortreturnriposteOriginFRMrejoindre→MErejoinder→ENrejoinder From Middle English rejoinder, rejonder, rejoynder, from Middle French rejoindre, with infinitive used as noun frequent in Law French. Doublet of rejoin.