σκιάω
From LSJ
κεραυνὸν ἐν γλώττῃ φέρειν → carry a thunderbolt on his tongue
English (LSJ)
A = σκιάζω, overshadow, make shady, Λῆμνον . . ἀκροτάτῃ κορυφῇ σκιάει A.R.1.604, cf. Arat.864, Nic.Th.30:—Pass., to be shaded or dark, δύσετό τ' ἠέλιος σκιόωντό τε πᾶσαι ἀγυιαί (Ep.3pl. impf.) Od. 2.388, al., cf. Arat.600.