Henry George Liddell, Robert Scott, A Greek-English Lexicon

A.“οἷόπερ” A.R.1.1325 ; in Ion. writers and in Poets the obl. cases are sts. borrowed from the Art., “τόπερ” Id.3.1098 ; “τοῦπερ” A.Pers. 779 ; “τῇπερ” Il.24.603, Hdt.1.30 ; “τοίπερ” Od.13.130 ; “τάπερ” A.Ch.418 (lyr.), Hdt.3.16 ; “τῶνπερ” Il.13.638, A.Ag.974 ; on concord and constr. cf. “ὅς” B. 1.1,2,4, 11.1a,3, IV. 4:—the very man who, the very thing which; freq. indistinguishable from simple ὅς, cf. “ὅσος” 111.4 : with words intervening between ὅς and περ“, ὅς ῥ᾽ ἔβαλέν περ” Il.4.524, cf. 13.101, etc.

2. used after Adjs. of resemblance, “ὡυτὸς ὅσπερ” Hdt.8.42 ; “ἐκ τῶν ἴσων . . , ὧνπερ αὐτὸς ἐξέφυ” S.OT1499 ; ὅμοια ἔπραττον ἅπερ ἄν . . X.An.5.4.34 ; ὅρκια τάπερ τε . . the same as . . , Hdt.1.74.

II. special uses of cases,

1. ὅπερ, wherefore, D.S.13.18 codd. (s.v.l.); although, A.D.Pron.103.7.

2. ἅπερ, as, like, A.Ch.381 (lyr.), Eu.131, 660, S.Aj.168 (anap., as v.l.), OT 175 (lyr.), X.HG5.1.18, etc.; cf. καθάπερ.

3. οὗπερ, v. ὅς A b. 1.

4. ᾗπερ, Dor. ᾇπερ, which way, where, whither, Il.6.41, 12.33, X.An.6.5.10, etc.; Ion. “τῇπερ, ἔθαψαν . . τῇπερ ἔπεσε” Hdt.1.30 ; also, as, Il.7.286, A.Ch.440(lyr.), Ar.Ach.364 ; “ᾗπερ δή” Il.9.310 ; “ᾗπερ καί” X.Mem.3.8.2.

5. in the Logic of Aristotle, ὅπερ ἐστί, or ὅπερ alone, has two senses :

a. non-technical, and unemphatic, what (a thing) is, ἑκάστη οὐσία τοῦθ᾽ ὅ. ἐστίν, οὐ λέγεται μᾶλλον καὶ ἧττον each substance is called what it is without the difference of more or less, Cat.3b36 ; τὸ διπλάσιον τοῦθ᾽ ὅ. ἐστίν, ἑτέρου λέγεται the double is called what it is (viz. the double) of something, i.e. is relative, ib.6a39.

b. expressing identity, οὔτε ἡ χιὼν ὅ. λευκόν snow is not what white is, i.e. is not identical with white, Top.120b23 ; ὁ λευκὸς ἄνθρωπος οὐκ ἔστιν ὅ. χρῶμα ib.116a27: hence, to indicate the precise or essential nature of a thing, οὐ γὰρ ἂν φαίη ὅ. κακόν τι εἶναι τὴν ἡδονήν he would not say that pleasure is essentially something bad, EN1153b6; τὰ μὲν οὐσίαν σημαίνοντα ὅ. ἐκεῖνό ἢ ὅ. ἐκεῖνό τι σημαίνει expressions which show the essence show precisely what the thing in question is or precisely of what kind it is (i.e. indicate either its species or its genus), APo.83a24 ; ὅ. <τόδε> τί ἐστι τὸ τί ἦν εἶναι the essence of a thing is precisely a 'this', i.e. a fully specified particular, Metaph.1030a3; ἡ μὲν [ἐπιστήμη] ὅ. ἀνθρώπου ἐστίν knowledge (that man is an animal) is apprehension that 'animal' is an element in the essential nature of man, APo.89a35.