PRIMORDIUM Meaning of PRIMORDIUM in English [ prʌɪ'mɔ:dɪəm ]■ noun ( plural primordia -dɪə ) Biology an organ, structure, or tissue in the earliest stage of development.OriginC19: from L., neut. of primordius . Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004