confidence > hardihood

4 Full oft approved in many a cruel war,

Full > Exceedingly approved > tested

5 The brother of Cymochles, both which are

Cymochles > "Wavering Troublemaker" (Greek kyma, wave, ochleo, to disturb, cause trouble) which > of whom

6 The sons of old Acrates and Despite,

Acrates > "Without Control", "Intemperate" (Greek; cf. "Acrasia",
201.51:2)
Despite > Rage

7 Acrates, son of Phlegethon and Jar;

Phlegethon > (The "Stream of Fire": one of the five rivers of hell, though which fire flows instead of water) Jar > Discord

8 But Phlegethon is son of Erebus and Night;