ἐξ ἐπιδρομῆς

From LSJ

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

Source

Greek > English (Woodhouse)

off-hand, off hand, offhand, on the spur of the moment