The quality or state of being blobby; shapelessness or the characteristic of having a blob-like appearance.
From 'blobby' (adjective formed from 'blob' plus '-y') plus '-ness' (abstract noun suffix from Old English). This creates a noun from an adjective.
The '-ness' suffix is one of the most productive noun-making tools in English—you can add it to almost any adjective to create an abstract noun (happy→happiness, sad→sadness, blobby→blobbiness).
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