Is gunned the engine a metaphor?

The phrase "gunned the engine" is not a metaphor. It's a literal description of an action.

Here's why:

* Metaphor: A metaphor uses figurative language to compare two unlike things. For example, "He was a lion in battle" compares the man's bravery to a lion's strength, but they are not actually the same thing.

* Literal: A literal description uses language to describe something as it actually is. "Gunned the engine" literally describes the action of pressing down on the accelerator pedal to increase the engine's speed.

Therefore, "gunned the engine" simply means accelerated the vehicle and doesn't involve any figurative comparisons.