1. usus: usus rerum (☞ experientia unclassical in this sense; Cels., praef.). Sometimes prudentia (the cautious judgement, such as experience would give). From experience, re doctus (Cic., Fam., 13, 5, 1); expertus; usu doctus (Caes.): by or from one’s own experience, expertus; expertus in se (e.g., illud tibi expertus promitto: omnia, quae dico, dico expertus in nobis, Cic., Planc., 9, 22). Experience in the management of political affairs, usus reipublicae; great, usus in republica rerum maximarum: military experience, in castris usus: experience in nautical affairs, scientia atque usus rerum nauticarum: a man of great experience, vir plurimo rerum usu, or magno usu praeditus, or (Caes.) usu atque exercitatione praeditus; vir usu et prudentia praestans; vir multis experimentis eruditus (Plin., Ep., 1, 5, 16): to have had great military experience, magnum in re militari usum habere (Caes.); magnum in castris usum habere (Liv.): having had no military experience, nullo (etiam nunc) usu rei militaris percepto (Caes.): to be considered a general of no experience, nullius usus imperatorem haberi (Caes.): to have had no great (military) experience, non magnum rei militaris usum habuisse (Caes.): to be gaining experience, usum consequi: to have or possess experience, usum babere; usu praeditum or imbutum esse; aetate et usu doctum esse; in anything, usum alicujus rei percepisse; great experience in anything, magnum usum habere in re: great and varied experience, multarum rerum usum habere: to know by or from experience, expertum scire (☞ experientia edoctum scire not good); experientia didicisse; usu cognitum habere (aliquid): which I know from experience, quod me docuit usus; *quod scio expertus in me (from personal experience of it in my own case): to know from long experience, cognitum habere observatione diuturna (after Cic., de Divin., 2, 12, 28): what they have learned from books, I have learned from experience in the field, quae illi litteris, ea ego militando didici (Sall., Jug., 85, 13): to know anything more from experience than from books, experiendo magis quam discendo cognovisse: it is very difficult to form an opinion without experience, judicare difficile est sane nisi expertum. I speak (i. e., in a letter) from experience, expertus scribo, quae scribo: I can recommend this method of cultivation from experience, hunc ordinem culturae experti comprobavimus: I have had personal experience of etc., in me ipso expertus sum, ut etc.: I answer according to my own experience, id respondeo, quod animadverti: taught by the experience of others, per aliena exempla doctus; per aliena experimenta doctus (Tac., Agr., 19, 1): a very careful person of great experience, experientissimus ac diligentissimus (e.g., arator): experience has taught, experimentis cognitum est (Tac., Ann., 12, 14, 2); usus docuit (e.g., id verum esse, Sall.): anything of which we have had experience, aliquid expertum (passive) perspectumque (Cic., Balb., 6, 16). Many lessons are taught us by experience, dies multa affert.