Definition of "selfsame"

For both of you are Birds of ſelfe-ſame Feather.

c. 1591–1592 (date written), William Shakespeare, “The Third Part of Henry the Sixt, […]”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act III, scene iii], page 162, column 1

In my ſchoole dayes, vvhen I had loſt one ſhaft [i.e., arrow], / I ſhot his fellovv of the ſelfe-ſame flight / The ſelfe-ſame vvay, vvith more aduiſed vvatch / To finde the other foorth, and by aduentring both, / I oft found both. I vrge this child-hoode proofe, / Becauſe vvhat follovves, is pure innocence.

c. 1596–1598 (date written), W[illiam] Shakespeare, The Excellent History of the Merchant of Venice. […] (First Quarto), [London]: […] J[ames] Roberts [for Thomas Heyes], published 1600, [Act I, scene i]

He and his Horse, were of a piece. / One Spirit did inform them both, / The self-same Vigor, Fury, Wroth: […]

1662, [Samuel Butler], “[The First Part of Hudibras]”, in Hudibras. The First and Second Parts. […], London: […] John Martyn and Henry Herringman, […], published 1678; republished in A[lfred] R[ayney] Waller, editor, Hudibras: Written in the Time of the Late Wars, Cambridge: University Press, 1905, canto II, page 40

He trod the very ſelf-ſame ground you tread, / And victory refuted all he ſaid.

1781 (date written), William Cowper, “Table Talk”, in Poems, London: […] J[oseph] Johnson, […], page 21

Mine be the strength of spirit fierce and free, / Like some broad river rushing down alone, / With the selfsame impulse wherewith he was thrown / From his loud fount upon the echoing lea:— […]

1832 December (indicated as 1833), Alfred Tennyson, “Sonnet”, in Poems, London: Edward Moxon, […], page 1

And Quack and Dupe, as we must ever keep in mind, are upper-side and under of the self-same substance; convertible personages: turn up your dupe into the proper fostering element, and he himself can become a quack; […]

1843 April, Thomas Carlyle, “Morrison’s Pill”, in Past and Present, American edition, Boston, Mass.: Charles C[offin] Little and James Brown, published 1843, book I (Proem), page 26

But in [Isaac] Newton, science was as easy as breathing; he used the same wit to weigh the moon that he used to buckle his shoes; and all his life was simple, wise, and majestic. So it was in Archimedes,—always self-same, like the sky.

1870, Ralph Waldo Emerson, “Works and Days”, in Society and Solitude. Twelve Chapters, Boston, Mass.: Fields, Osgood, & Co., page 164

[T]hrough my police issue 200 × 6000 macroscopic laser-prism binoculars I could see he was the same guy who had just bopped the doorman in the head. […] But you can imagine my surprise when I angled said state-of-the-art bins to the street, watched the long black car as it rolled up and saw the self-same guy step out of it.

1992, Robert Rankin, chapter 12, in The Suburban Book of the Dead: Armageddon III: The Remake, London: Bloomsbury Publishing, page 131

I preſent vvhat here is to you, vvherein you ſhall receive but the ſelfeſame by Number and by Meaſure; vvhich, before, you had by VVeight.

1634, Fra[ncis] Quarles, “Mildreiados. To the Blessed Memory of that Faire Manuscript of Vertue and Unblemisht Honour, Mildred, La[dy] Luckyn; […]. To My Honourable and Deare Friend, Sr William Luckyn, Baronet.”, in Divine Poems: […], revised edition, London: […] M[iles] F[lesher] for I[ohn] Marriot, […], page 518

So ſtrictly is the Specific Nature preſerv'd in the Individuals of the ſame kind, vvho all equally partake of it, and are ſo very reſembling and uniform in it, that they ſeem but as ſo many Self-ſames, ſo many Reproductions of one thing, like the Image of the ſame Face repeated by a Multiplying Glaſs. Thus for Inſtance, in Men, there is the ſame common Human Nature in all of them vvithout Intenſion or Remiſſion, the ſame Intellectual Frame, the ſame thinking Principle, the ſame rational Faculties, the ſame Radical Deſires and Inclinations, the ſame Natural Affections, the ſame Springs of Paſſion, &c.

1701, John Norris, “The Reality of the Distinction Justifi’d, by Shewing that This is Not the Only State of Things, but that They Have an Ideal as Well as a Natural State”, in An Essay towards the Theory of the Ideal or Intelligible World. […], part I, London: […] [Samuel] Manship, […]; and W[illiam] Hawes, […], page 50