πταίω

A. πταίσω D. 2.20: aor. ἔπταισα Hdt. 9.101, etc.: pf. ἔπταικα Men. 675, Bato 1, Plb. 3.48.4, (προς‐) Isoc. 6.82:— Pass., v. infr.1:

I. trans., cause to stumble or fall, σύνθεσιν ποτὶ ψεύδει Pi. Fr. 205, cf.LXX 1 Ki. 4.3:—Pass., to be missed, of things, Ael. NA 2.15; τὰ πταισθέντα failures, errors, Luc. Demon. 7; ἃ ἐπταίσθη his failures, Plu. Comp.Dion.Brut. 3.

II. intr., stumble, trip, fall, π. πρός τινι stumble against, fall over, π., ὥσπερ πρὸς ἕρματι, πρὸς τῇ πόλει Pl. R. 553b, cf. A. Pr. 926, Theoc. 7.26; πρὸς τὰς πέτρας cj. in X. An. 4.2.3; prov., μὴ δὶς πρὸς τὸν αὐτὸν λίθον πταίειν Plb. 31.11.5; also π. περί τινι, μὴ περὶ Μαρδονίῳ πταίσῃ ἡ Ἑλλάς lest Hellas should get a fall over him, i.e. be defeated by him, Hdt. 9.101.

2. metaph., make a false step or mistake, Th. 2.43, D. 2.20, Men. 672, etc.; ἐὰν πταίωσί τι when they make a blunder, of medical men, Philem. 75.5; οὐκ ἐλάττω, ἐλάχιστα, τὰ πλείω π., Th. 1.122, 4.18, 6.33; ἔν τισι D. 18.286; λογισμοῖς Men. 380; τῇ μάχῃ, τοῖς ὅλοις, τοῖς πράγμασι, etc., Plb. 18.14.13, 3.48.4, 1.10.1, etc.; ἀψευδὴς ὢν καὶ μὴ π. τῇ διανοίᾳ περὶ τὰ ὄντα Pl. Tht. 160d; also π. ὑπ’ ἀνάγκας S. Ph. 215 (lyr.); ὑπό τινος π. τῇ πατρίδι Plb. 5.93.2; ἐκ τύχης Id. 2.7.3.

3. π. τῆς ἐλπίδος to be baulked of . ., Hdn. 8.5.1.

4. ἡ γλῶττα π. stutters, Arist. Pr. 875b19.