ἐπὶ ξυροῦ γὰρ ἀκμῆς ἔχεται ἡμῖν τὰ πρήγματα → our affairs are balanced on a razor's edge, our affairs are set upon the razor's edge
P. and V. φλόξ, ἡ, πῦρ, τό; see fire.
