ἴῃ

From LSJ

ξένῳ δὲ σιγᾶν κρεῖττον ἢ κεκραγέναι → it's better for a stranger to keep silence than to shout (Menander)

Source

French (Bailly abrégé)

3ᵉ sg. sbj. prés. de εἶμι.

Russian (Dvoretsky)

ἴῃ: 3 л. sing. praes. conjct. к εἶμι.