A.communicate with, “τῷ ἔξω χωρίῳ” Hp.Prog.7; “ἀλλήλοις” Pl.Sph.251d; of troops in order of battle, to be in touch with, “τοῖς ἄκροις” Ascl.Tact.1.3; “ἐ. πᾶσαι αἱ ἐπιστῆμαι ἀλλήλαις κατὰ τὰ κοινά” Arist.APo.77a26; τίνι οὐκ ἐ. [τὸ μάθημα] τῶν ἐπικαιροτάτων ἐν ἰητρικῇ; Hp.Fract.31, cf. Pl.Grg.464c: c. dat. pers., D.29.36.
2.. share in a thing with one, τῶν γραμμάτων τί ἐπικοινωνεῖ; what letters has it in common? Pl.Cra..394c; νόμος οὐδὲν ἐπικοινωνῶν τῷ περὶ τῶν στεφανουμένων νόμῳ having nothing in common with . . , Aeschin.3.44: generally, share in, c.gen., Ph.1.561.
3.. to be in partnership with, c. dat., POxy.1280.6 (iv A.D.).