[f. WHAT pron. + -NESS; transl. L. quidditās QUIDDITY.] That which makes a thing what it is; essential nature, essence: = QUIDDITY 1.

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1611.  Florio, Quidità, the whatnesse of any thing.

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1627.  W. Sclater, Expos. 2 Thess. (1629), 39. The kinde or quality or if you’l so terme it, whatnesse of it.

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1656.  [? J. Sergeant], trans. T. White’s Peripat. Inst., 198. The Understandablenesse of a thing, or the quiddity, the Whatnesse.

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1870.  Morley, Stud. Lit. (1891), 266. Pressing for definition, you never get much further than that each given quiddity means a certain Whatness.

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1889.  Mivart, Truth, 212. We must … have the conception of the kind of thing the object is—‘what’ it is, or the idea of its ‘whatness.’

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  † b.  Used by N. Fairfax for: Statement of what a thing is, definition. Obs. nonce-use.

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1674.  N. Fairfax, Bulk & Selv., 80. The definition or whatness of a thing ought to be of a thing as a thing.

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