The definition of "same".
This is the best I could find, but it leaves out common usage such as in Bahasa Malayu, mathematics, science and the ridiculous use in legalese to confuse the common folk.
1. from Middle English same, samme, samen; from (a) Anglo-Saxon same, similarly, in the same way, used only in combination with swā, so, as (swā same swā, the same as); cf. sam, conjunction, whether, or (sam … sam, whether … or); as a prefix sam,- denoting agreement or combination; = Old Saxon sama, samo, same = Middle Low German same, sam = Old High German sama, Middle High German same, sam, adverb, the same, likewise; (b) Anglo-Saxon samen, together, = Old Saxon saman = OFries. semin, samin, samen = Middle Low German samene = Old High German samant, Middle High German sament, samt, German samt, sammt, zu-sammen, together, together with, = Icelandic saman = Swedish samman = Danish sammen = Gothic (Moesogothic) samana, together, = Russian samnu, together; (c) as an adjective not in Anglo-Saxon, but of Scandinavian origin, from Icelandic samr = Swedish samma, samme = Danish samme = Old High German sam = Gothic (Moesogothic) sama, the same; = Greek ἅμα, at the same time, together, ὁμός, the same (later ὁμοίος, like), = Sanskrit sama, even, like, equal; cf. Sanskrit sa (in comp.), with, sam, with; Latin simul, together, similis, similar: see simultaneous, similar, etc.
2. from Middle English same, from Icelandic samr = Swedish samma, samme = Danish samme = Old High German sam = Gothic (Moesogothic) sama, the same: see same, adv.
1. Together. So ryde thay of by resoun bi the rygge bonez, Euenden to the haunche, that henged alle samen, & heuen hit vp al hole, & hwen hit of there. Sir Gawayne and the Green Knight (E. E. T. S.), l. 1345. On foote & on faire horsse fought thei samme. Alisaunder of Macedoine (E. E. T. S.), l. 342. For what concord han light and darke sam? Spenser, Shep. Cal., May.
2. Identical numerically; one in substance; not other; always preceded by the definite article or other definitive word (this or that). In this sense, same is predicable only of substances (things or persons), or of other kinds of objects which, having individuality are for the purposes of speech analogous to individual things, especially places and times. It is a relative term, implying that what comes to mind in one connection and what comes to mind in another connection are one individual or set of individuals in existence. The very same man that beguiled Master Slender of his chain cozened him of it. Shak., M. W. of W., iv. 5. 37. There was another bridge … built by the same man at the same time. Coryat, Crudities, I. 29. The very same dragoons ran away at Falkirk that ran away at Preston Pans. Walpole, Letters, II. 3.
3. Of one nature or general character; of one kind, degree, or amount: as, we see in men everywhere the same passions and the same vices; two flames that are the same in temperature; two bodies of the same dimensions; boxes that occupy the same space. Same, used in this way, expresses less a different meaning from def. 1, than a different (and often loose) mode of thinking; the thought is often that of equality rather than that of identity. Those things, says the Philosopher, are the same whose essence are one and the same. … Those things are said to be the same, says the Philosopher, in number, whose matter is one and the same. … Those things are the same in species whose ratio of essence is one. Burgersdicius, tr. by a Gentleman, i. 20. I rather pity than hate Turk and Infidel, for they are of the same Metal and bear the same Stamp as I do, though the Inscriptions differ. Howell, Letters, I. vi. 32. It hath bin inevitably prov'd that the natural and fundamental causes of political happines in all governments are the same. Milton, Reformation in Eng., ii. Ignatius Loyola … in the great Catholic reaction bore the same part which Luther bore in the great Protestant movement. Macaulay, Von Ranke's Hist. Popes. Bigotry is the same in every faith and every age. Prescott, Ferd. and Isa., ii. 6. The same sentiment which fits us for freedom itself makes us free. H. Spencer, Social Statics, p. 467. This ambiguity in the word same, whereby it means either individual identity or indistinguishable resemblance, has been often noticed, and from a logical or objective point of view justly complained of, as “engendering fallacies in otherwise enlightened understandings.” J. Ward, Encyc. Brit., XX. 81.
4. Just mentioned, or just about to be mentioned or denoted: often used for the sake of emphasis or to indicate contempt or vexation. Who is the same, which at my window peepes? … Is it not Cinthia? Spenser, Epithalamion, l. 372. For that same word, rebellion, did divide The action of their bodies from their souls. Shak., 2 Hen. IV., i. l. 194. Afterwards they flea him, and, obseruing certaine cere monies about the flesh, eat the same. Purchas, Pilgrimage, p. 425. No one was there that could compare With this same Andrew Lammie. Andrew Lammie (Child's Ballads, II. 191).
5. All the same nevertheless; notwithstanding; in spite of all: for all that. We see persons make good fortunes by them all the same. Disraeli, Coningsby, iv. 9.
6. At the same time. At one time; not later.
7. At the same time. However; nevertheless; still; yet: used to introduce a reservation, explanation, or fact not in conflict but in contrast with what has been said. Sir Peter. We shall now be the happiest couple— Lady T. And never differ again? Sir Peter. No, never!—though, at the same time, indeed, my dear Lady Teazle, you must watch your temper very seriously. Sheridan, School for Scandal, iii. 1.