σημαίνω σῆμα to shew by a sign, indicate, make known, point out, Hom., etc. absol. to give signs, make signals, Il., Trag. to give a sign or signal to do a thing, Il.; c. inf., Hdt., etc.; μὴ σημήναντός σου without any order from you, Plat.:—c. gen. to bear command over, τινός or ἐπί τισι Hom.: absol. to give orders, Hom.; σημαίνων σημάντωρ, Soph. in war, to give the signal of attack, Thuc.; ση. τῆι σάλπιγγι Xen.; ση. ἀναχώρησιν to make signal for retreat, Thuc.:—impers., σημαίνει (sc. ὁ σαλπιγκτής) signal is given, τοῖς Ἕλλησι ὡς ἐσήμηνε when signal was given for the Greeks to attack, Hdt.; ἐσήμαινε πάντα παραρτέεσθαι signal was given to make all ready, Hdt. to signify, indicate, announce, declare, Eur., Hdt., Attic generally, to signify, interpret, explain, Hdt., Aesch.; absol., σήμαινε tell, Soph. = σφραγίζω, to stamp with a sign or mark, to seal, Lat. obsignare, mostly in Mid., Xen.:—Pass., εὖ σεσημάνθαι to be well sealed up, Ar.; τὰ σεσημασμέναι, opp. to τὰ ἀσήμαντα, Dem. Mid. σημαίνομαι, like τεκμαίρομαι, to give oneself a token, i. e. conclude from signs, conjecture, Soph. to mark for oneself, σημαίνεσθαι βύβλωι (sc. βοῦν), i. e. by sealing a strip of byblus round his horn, Hdt.