Part of Speech: Verb

Definition: to make (someone) more confident

Source: http://www.merriam-webster.com/dictionary/emboldened

Meaning: I read this word while reading the tunnel rats in the lines Thus emboldened, I scrambled down a ladder….

Now that I know what embolden means in this context it meant that Yonette Joseph was confident going the manhole to dig out the treasure under it.