ὅστις
I. "any one who, anything which", i. e. "whosoever, whichsoever", differing from ὅς, as Lat. quisquis, from "qui", Hom., etc.; ὅντινα κιχείη "whomsoever" he caught, Il.; ὅτις κ ἐπίορκον ὀμόσσῃ "whoso" forswears himself, id=Il., etc.: —ἔστιν ὅστις, Lat. est qui, often with a negat., οὐκ ἔστιν ὅτῳ μείζονα μοῖραν νείμαιμ᾽ there is no "one to whom" I would give more, Aesch., etc.: —οὐδὲν ὅ τι οὐ "everything", Hdt.
II. hardly different from ὅς, "who", βωμόν, ὅστις νῦν ἔξω τῆς πόλεώς ἐστι the altar, which.., Thuc.
III. in "indirect" questions, ξεῖνος ὅδ᾽, οὐκ οἶδ᾽ ὅστις Od.:—in dialogue, when the person questioned repeats the question asked by τίς, as οὗτος τί ποιεῖς; Answ. ὅ τι ποιῶ; [you ask] "what" I'm doing? Ar.
IV. neut. ὅ τι used absol. as a Conjunction, v. ὅ τι.
V. ἐξ ὅτου "from which time", Soph., etc.
2. "from what cause", id=Soph., Eur.