to become more interesting and exciting, or to make something become like this

A new coat of paint would liven the kitchen up. 新刷一层漆会使厨房鲜亮起来。

Liven up your meals with fresh herbs and spices. 新鲜的香料和调味品会让饭菜的味道更加鲜美。

The party livened up as soon as Sally arrived. 萨莉一到，晚会立刻活跃了起来。

to become more energetic or in a better mood, or to make someone feel this way

She was subdued to start with, but after a while she livened up. 刚开始的时候她有点儿沉默，但过了一阵就活跃起来了。

I'm going to liven myself up a little by going for a run. 我要去跑跑步换换心情。