Definition of frustule in US English:



  • The silicified cell wall of a diatom, consisting of two valves or overlapping halves.

    • ‘Observe the diatom frustule below at right, in which the two halves have been pushed slightly askew.’
    • ‘Because the frustule cannot grow once it has been laid down, the mean size of a dividing population of diatoms gets smaller and smaller with time.’
    • ‘Bacteria accelerate silica dissolution in the sea by colonizing and enzymatically degrading the organic matrix of diatom frustules.’
    • ‘The following group of pictures is of diatom frustules which have been prepared by treatment with strong acid to remove all organic traces in order to best display the intricate frustule markings.’
    • ‘Like its brethren, it is encased by a frustule, a rigid cell wall delicately marked with pores in patterns distinctive enough for scientists to tell the species apart.’


Mid 19th century: from Latin frustulum, diminutive of frustum (see frustum).