Black omen, for an omen that portends bad fortune:

Ater odor.
Virgil.

The peculiar beauty of this figure arises from suggesting a comparison.

3. A word proper to the subject, employ’d to express one of its attributes.

Mens for intellectus. Mens for a resolution.

Istam, oro, exue mentem.

4. When two subjects have a resemblance by a common quality, the name of the one subject may be employ’d figuratively to denote that quality in the other.

Summer life for agreeable life.

5. The name of the instrument, made to signify the power of employing it.

—— Melpomene, cui liquidam pater
Vocem cum cithara dedit.