The daring step out to defy danger; the dauntless will not flinch before anything that may come to them; the doughty will give and take limitless hard knocks.

J. C. Fernald, English Synonyms and Antonyms (1914)

Example sentences

brave When it comes to war, they are as brave as anyone.
fearless I want to find my energetic, fearless brother.
valiant Her appearance presented a valiant attempt at smartness.
intrepid Many tried to carry out the deed of the intrepid mountaineer.

Popularity over time

Word	1850 → 2019	Trend
dauntless		steady
brave		rising
fearless		rising
valiant		steady
intrepid		rising

Use in printed books, per decade from 1850 to 2019.

By length

4 letters: game¹, bold¹
5 letters: brave¹, hardy², gutsy²
6 letters: heroic³, daring², plucky²
7 letters: valiant², gallant², doughty²
8 letters: fearless², resolute³, intrepid³, stalwart², valorous
9 letters: daredevil³, audacious³, undaunted³, unfearing
10 letters: courageous³
11 letters: indomitable⁵
13 letters: unconquerable

The small number after each word is its number of syllables (hardy² = 2 syllables).