confirmitas

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)

Latin > English (Lewis & Short)

con-firmĭtas: ātis, f.,
I firmness of will; in a bad sense, obstinacy, Plaut. Mil. 2, 2, 34 Brix. (the verse is rejected by Lorenz).