What is the simile as lively a?

"As lively as" is not a simile by itself. It's the beginning of a simile. To make it a complete simile, you need to add a second part that compares the first thing to something else.

For example:

* As lively as a puppy: This compares someone or something to the energy and enthusiasm of a puppy.

* As lively as a spring day: This compares something to the freshness and vibrancy of a spring day.

* As lively as a dance floor: This compares something to the energy and movement of a dance floor.

To complete the simile, you need to fill in the blank after "as lively as" with a noun or phrase that makes the comparison clear.