Definition of "unfounded"

[…] my chiefest design ever since the seventeenth year of my age […] consisted in elaborating such demonstrations in Natural Philosophy, as might serve to unfold the natures of Beings in relation to the Art of Physick, hitherto so uncertain, blind, and unfounded on Art […]

1663, Gideon Harvey, “To the Reader”, in Archelogia Philosophica Nova, or, New Principles of Philosophy‎, London: Samuel Thomson

[…] such unfounded conjectures are best answered by neglect.

1798, Thomas Robert Malthus, An Essay on the Principle of Population‎, London: J. Johnson, Chapter 11, p. 61, footnote

The gloom of her first anticipations was proved to have been unfounded.

1814 July, [Jane Austen], chapter XVIII, in Mansfield Park: […], volumes (please specify |volume=I to III), London: […] T[homas] Egerton, […]

“He give a name,” said Mrs. Hall—an assertion which was quite unfounded—“but I didn’t rightly hear it.”

1897, H[erbert] G[eorge] Wells, chapter 4, in The Invisible Man: A Grotesque Romance, New York, N.Y., London: Harper & Brothers Publishers

[…] the allegation that his lordship never allowed Jewish people to enter the house or any Jewish staff to be employed is utterly unfounded […]

1989, Kazuo Ishiguro, “Day Three, Morning”, in The Remains of the Day‎, Vintage International, published 1990, page 137

Even the great world as yet undiscovered, the cities as yet unfounded, and the history as yet unwritten, are lost: fallen from the beginning.

1980, Helen Louise Gardner, John Carey, English Renaissance studies, page 268

[…] from them I goThis uncouth errand sole, and one for allMy self expose, with lonely steps to treadTh’ unfounded deep […]

1667, John Milton, “Book II”, in Paradise Lost. […], London: […] [Samuel Simmons], […]; republished as Paradise Lost in Ten Books: […], London: Basil Montagu Pickering […], 1873, lines 826-829

He makes this Glob so spacious and fairUnfix’d, unprop’d, unfounded any where,Hang, like a Water-bubble in the Air.

1685, William Clark, The Grand Tryal, or, Poetical Exercitations upon the Book of Job‎, Edinburgh, Part 3, Chapter 26, p. 210