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)
adj.
P. and V. αὐθάδης, σκληρός, σχέτλιος; see also harsh.