dauntless
DAWNT-lisadjMeaning not discouraged by danger or difficulty
Memory hook DAWN-TLESS: out at DAWN in any storm. Every day at dawn, through snow and howling wind, Greta delivers the mail. No storm can discourage her: she is dauntless.
The dauntless mail carrier delivered every letter through the blizzard.
In context After three failed launches, a weaker team might have quit, but the dauntless engineers fixed the valve, checked every bolt and tried again the next morning.
Similar undaunted, fearless, brave, unflinching
Opposite fainthearted, timid, discouraged
Daunt comes from Old French danter, “to tame, subdue,” from Latin domitare (to tame); add -less, “without.”