5 cuneum: here = the convex formation of the Gauls and Spaniards.
8-9 in mediam aciem = the centre of the line, i.e. of the Gauls and Spaniards, who were intended to engage with the Romans first.
10 subsidia = reserves, i.e. the Africans, on the right and left.
14-16 Afri circa . . . alas. Hannibal’s formation is now reversed.* The horns (cornua) of the semicircle (the Africans) are now advanced, and outflanked (circumdedere alas) the Romans, who rushed heedlessly into the intervening space (in medium, i.e. the concave part of H.’s line formed by the retirement of the Gauls and Spaniards).
21-22 recentibus ac vegetis = fresh in body and mind.
* i.e. the Africans now formed the horns of a crescent in relation to their centre, while it formed the concave part of the crescent.—D.
Results of the Battle. Hannibal becomes master of Magna Graecia, and the Romans lose (including 23,000 taken prisoners) about 70,000 men.