μὴ ἐν πολλοῖς ὀλίγα λέγε, ἀλλ΄ ἐν ὀλίγοις πολλά → don't say little in many words, but much in a few words (Stobaeus quoting Pythagoras)
P. and V. ἀμήχανος (rare P.), ἄπορος, δυσχερής, προσάντης, V. δυσπετής, δύσχιμος, Ar. and P. χαλεπός; see difficult, laborious.
