Boldly
Bravely, Fearlessly
adjective, adverb
If you have a daring nature you'll boldly go where no one else has gone before!
Note that you need to add と to the end of this word to make it an adverb, and たる to make it an adjective!
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
あの男は、まるで自分の意志で敢然と難局に立ち向かっているつもりなのよ。
That man plans to boldly oppose the difficult situation with nothing but his own determination.