ἢ δεῖ σιωπᾶν ἢ λέγειν τὰ καίρια → you should either keep silence or make timely remarks (Menander)
subs.
P. and V. διαφορά, ἡ, ἔρις, ἡ, στάσις, ἡ, Ar. and V. νεῖκος, τό (also Plat. but rare P.).