- An aggregation of cells in the embryo indicating the first trace of an organ or structure. SYN: anlage (1). [L. origin, fr. primus, first, + ordior, to begin]- genital p. ovoid clump of cells seen in the rhabditiform larvae of Strongyloides stercoralis and hookworm that becomes the reproductive system.
* * *pri·mor·di·um -ē-əm n, pl -dia -ē-ə the rudiment or commencement of a part or organ: ANLAGE <the gonadal \primordium>
* * *pri·mor·di·um (pri-morґde-əm) pl. primorґdia [L. â€œthe beginningâ€] the earliest discernible indication during embryonic development of an organ or part; called also anlage or rudiment.
Medical dictionary. 2011.