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)
δεκαέτης -ες of δεκαετής -ές [δέκα, ἔτος] tienjarig.
(see also: δεκαετής) lasting ten years