00018: 18. ἀγαθός [deriv. uncertain] 0. good, Lat. bonus: I. of persons, 1. in early times, good, gentle, noble, in reference to birth, opp. to κακοί, πατρὸς δ᾽ εἴμ᾽ ἀγαθοῖο, θεὰ δέ με γείνατο μήτηρ Il.; ἀγαθοὶ καὶ ἐξ ἀγαθῶν, Lat. boni bonis prognati, Plat.; with this early sense was associated that of wealth and power, like Lat. optimus quisque in Sallust and Cicero; esp. in the phrase καλοὶ κἀγαθοί (v. καλοκἀγαθός).
2. good, brave, since these qualities were attributed to the Chiefs, Il.; ἀγαθὸς ἐν ὑσμίνῃ, βοὴν ἀγαθός, πὺξ ἀγαθός, etc., Hom.; ἀγ. τὰ πολέμια, τὰ πολιτικά Hdt., etc.;—also c. dat., ἀγ. πολέμῳ Xen.;—and, ἀγ. εἴς τι, περί τι, πρός τι Plat., etc.; lastly, c. inf., ἀγ. μάχεσθαι, ἱππεύεσθαι, good at fighting, etc., Hdt.
3. good, in moral sense, Plat., etc.
4. ἀγαθοῦ δαίμονος, as a toast, "to the good Genius," Ar.
II. of things, 1. good, serviceable, Ἰθάκη ἀγαθὴ κουροτρόφος Od.; ἀγ. τοῖς τοκεῦσι, τῇ πόλει Xen.; c. gen., εἴ τι οἶδα πυρετοῦ ἀγ. good for fever, id=Xen.; ἀγαθόν [ἐστι], c. inf., it is good to do so and so, Hom., etc.
2. ἀγαθόν, τό, a good, of persons, φίλον, ὃ μέγιστον ἀγ. εἶναι φασι Xen.; ἐπ᾽ ἀγαθῷ τοῖς πολίταις Ar.; τὸ ἀγαθόν or τἀγαθόν, the good, summum bonum, Plat., etc.; in pl., ἀγαθά, τά, the goods of fortune, wealth, Hdt., etc.; also good qualities, of a horse, Xen.
III. instead of the regular degrees of comparison, many forms are used,—comp. ἀμείνων, ἀρείων, βελτίων, κρείσσων, λωΐων , epic βέλτερος, λωΐτερος, φέρτερος; — Sup. ἄριστος, βέλτιστος, κράτιστος, λώϊστος, epic βέλτατος, κάρτιστος, φέρτατος, φέριστος.
IV. the adv. is usually εὖ: ἀγαθῶς in late writers.