Definition of primordium in English:


Pronunciation /prīˈmôrdēəm/ /praɪˈmɔrdiəm/


  • An organ, structure, or tissue in the earliest stage of development.

    ‘the primordium of the pituitary’
    ‘the axils of the leaf primordia’
    • ‘Although mitoses were still detected in leaf primordia of that stage, cell differentiation had already started.’
    • ‘In flowers, both genes are expressed throughout inflorescence and floral meristems and in developing organ primordia.’
    • ‘The development is initiated as a hyphal knot of 0.2 mm or less in diameter, which rapidly develops into a tiny primordium containing the rudimentary tissues of the future pileus and stipe.’
    • ‘These organ primordia, which develop after a period of time corresponding to winter in temperate regions, are called preformed organs.’
    • ‘Microscopical examination for the fungal infection was performed on the bristles, adjacent hypocotyl surface and the internal tissue of root primordia.’


Late 19th century from Latin, neuter of primordius ‘original’, from primus ‘first’ + ordiri ‘begin’.



/prīˈmôrdēəm/ /praɪˈmɔrdiəm/