Naming one thing by another that is connected to it: the part for the whole, the object for its owner, the place for the people, the cause for the effect.
In the Iliad
she was weaving a great web, a double purple cloak, and in it she embroidered the many battles of the horse-taming Trojans and the bronze-breastplated Achaeans, which they suffered on her account under the hands of Ares.
By saying that the battles are fought "under the hands of Ares," the line names the god of war to speak of war itself. The part for the whole sums up the conflict in the figure of him who embodies it.
Book III: The Duel of Paris and Menelaus, the narrator
and he drew back his spear again; and bronze Ares roared as much as nine or ten thousand men roar in war, when they join the strife of Ares.
Book V: The Aristeia of Diomedes, the narrator
To you the son of Cronus, of crooked counsels, gave in two parts: with the scepter he gave you to be honored above all, but he did not give you courage, which is the greatest power.
Book IX: The Embassy to Achilles, Diomedes
Subscription
The explanation of each passage, in every device and in every work, comes with a subscription.