Blob

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late Middle English (denoting a bubble): perhaps symbolic of a drop of liquid; compare with blotch, blubber1, and plop.

wiktionary

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Possibly formed through mimesis, similarly to bleb and blubber.

blob (plural blobs)

etymonline

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blob (n.)

"drop, globule," 1725, from a verb meaning "to make or mark with blobs" (early 15c.), which is perhaps related to bubble. The same noun was used 16c. in senses of "a bubble, a blister." Related: Blobby.