νέῳ δὲ σιγᾶν μᾶλλον ἢ λαλεῖν πρέπει → it's fitting for a young man to keep silence rather than to speak (Menander)
P. and V. λάθρα, λαθραίως (rare P.), P. κρύφα, Ar. and P. κρύβδην, V. κρυφῆ; (also Xen.), κρυφαίως, κρύβδα.
