1. σημεῖον · sēmeion — LSJ
mark by which a thing is known, Hdt. 2.38; σημεῖα τῶν δεδικασμένων . ., σημεῖα πάντων ὧν ἔπραξαν Pl. R. 614c; sign of the future, τυραννίδος σ. A. Ag. 1355; σ. λαβεῖν ἔκ τινος E. Hipp. 514; trace, track, σημεῖα δʼ οὔτε θηρὸς οὔτε του κυνῶν . . ἐξεφαίνετο S. Ant. 257, cf. El. 886; τῆς καταβάσεως X. An. 6.2.2; of a cork on a buoy, Paus. 8.12.1.
Dor., tomb, IG 12(3).452 (iv B.C.), CIG l.c.
sign from the gods, omen, S. OC 94; τὰ ἀπὸ τῶν θεῶν σ. γενόμενα Antipho 5.81, cf. Pl. Phdr. 244c, Ap. 40b, X. Cyr. 1.6.1; wonder, portent, LXX Ex. 4.8, al.; σ. καὶ τέρατα Plb. 3.112.8, Ev.Matt. 24.24, Ev.Jo. 4.48, cf. IPE l.c., D.S. 17.114; φόβηθρα καὶ σ. ἀπʼ οὐρανοῦ Ev.Luc. 21.11; esp. of the constellations, regarded as signs, δύεται σημεῖα E. Rh. 529 (lyr.), cf. Ion 1157.
sign or signal to do a thing, made by flags, ἀνέδεξε σημήϊον τοῖσι ἄλλοισι ἀνάγεσθαι he made signal for the rest to put to sea, Hdt. 7.128; signal for battle, τὰ σ. ἤρθη, κατεσπάσθη, Th. 1.49, 63, etc.; καθαιρεῖν τὸ σ. to take it down, strike the flag, as a sign of dissolving an assembly, And. 1.36; τὸ τῆς ἐκκλησίας σ. Ar. Th. 278; ὕστερος ἐλθεῖν τοῦ σ. Id. V. 690: generally, signal, σ. ὑποδηλῶσαί τινι ὅτι . . Id. Th. 1011; τὰ σ. αὐτοῖς ἤρθη Th. 4.42; τὸ σ. τοῦ πυρός, ὡς εἴρητο, ἀνέσχον ib. 111;
standard or flag, on the admiralʼs ship, Hdt. 8.92; on the generalʼs tent, X. Cyr. 8.5.13; ἔξω τῶν σ. out of the lines, ib. 8.3.19.
body of troops under one standard or flag, PAmh. 2.39.2 (ii B.C.); cf. σημεία I.2.
landmark, boundary, limit, ἔξω τῶν σ. τοῦ ὑμετέρου ἐμπορίου out of the limits of your commercial port, D. 35.28; of milestones, Plu. CG 7, Hdn. 2.13.9.
device upon a shield, Hdt. 1.171, E. Ph. 1114; upon ships, figure-head, Ar. Ra. 933, Th. 6.31, E. IA 255 (lyr.).
signet on ring, etc., Ar. Eq. 952, V. 585, Pl. Tht. 191d, al., X. HG 5.1.30, D. 42.2, PRev.Laws 26.5 (iii B.C.); figure, image, Διὸς κτησίου Anticl. 13; badge, τρίαιναν σ. θεοῦ A. Supp. 218: pl., written characters, γράψαι σημήϊα . . φωνῆς IG 14.1549 (Rome).
pl. (Dor.) σαμεῖα, stripes, ib. 5(1).1390.16 (Andania, i B.C.); clavi· σημεῖα, Gloss.
watchword, war-cry, Plb. 5.69.8; ἀπὸ σ. ἑνὸς ἐπιστρέφειν τὰς ναῦς Th. 2.90, cf. X. HG 6.2.28.
birthmark or distinguishing feature, Wilcken Chr. 76.14 (ii A.D.), Sammelb. 15.27 (ii A.D.), etc.
sign, token, indication of anything that is or is to be, S. OT 1059, E. Ph. 1332; σ. φαίνεις ἐσθλὸς . . γεγώς S. El. 24, cf. OT 710; τέχνης σ. τῆς ἐμῆς Id. Ant. 998; so later τὰ σ. τῶν καιρῶν Ev.Matt. 16.3, etc.
in reasoning, a sign or proof, Ar. Nu. 369, Th. 1.6, 10, And. 2.25, etc.; τούτων ὑμῖν σημεῖα δείξω Aeschin. 2.103, cf. 3.46; τάδε τὰ σ. ὡς . . X. Ages. 1.5; σ. εἰ . . Pl. Grg. 520e; ὅτι ἀγαθὸς ἦν . ., τοῦτο μέγιστον σ. Id. Min. 321b; τὸ μὴ ἐκδυθῆναι οὐδὲν σ. ἐστι is no proof to the contrary, Antipho 2.2.5; also, instance, example, Hp. VM 20; σημεῖον δέ· to introduce an argument, D. 21.149, Isoc. 4.86,107, etc.
in the Logic of Arist., a sign used as a probable argument in proof of a conclusion, opp. τεκμήριον (a demonstrative or certain proof), APr. 70a11, SE 167b9, Rh. 1357a33.
in Stoic and Epicurean philos., sign as observable basis of inference to the unobserved or unobservable, Epicur. Ep. 2p.43U., Phld. Sign. 27, al., S.E. M. 8.142, al.; περὶ σημείων (dub. sens.), title of work by Zeno, Stoic. 1.14.
Medic., symptom, Hp. Morb. 3.6, 15, Aret. SD 1.9, Gal. 1.313, 18(2).306.
= Lat. lenticula, a kind of skin-eruption, Cels. 6.5.1.
pl., shorthand symbols, Plu. Cat.Mi. 23, Gal. Libr.Propr. 1, POxy. 724.3 (ii A.D.), Lib. Or. 42.25.
critical mark, Heph. Poëm. p.73C., D.L. 3.65.
= στιγμή, mathematical point, Arist. APo. 76b5, Ph. 240b3, Euc. Def. 1, al.; also σ. (with or without χρόνου) point of time, instant, Arist. Cael. 283a11, Ph. 262b2sq.
in Prosody and Music, unit of time, Aristid.Quint. 1.14, Longin. Proll. Heph. 5.