The adjective audacious means someone who is willing to take risks in order to achieve something.

Synonyms are adventurous, bold, courageous, or foolhardy.

The word origins from Middle French (1540s) audacieux, from audace meaning “boldness”. It also comes from Latin audacia meaning “daring, boldness, courage”, from audax meaning “brave, bold, daring”, from audere meaning “to dare, be bold”. In English, the bad sense of “shameless, unrestrained by propriety” is attested from 1590s.

In their opinion, the plan was audacious to explore the forest.

People can make an audacious decision for their own sake.

So audacious of her to take such action in this situation.