Other forms: unflinchingly
Use the adjective unflinching to describe someone who's fearless and steadfast, even when they're facing something very difficult. Martin Luther King, Jr. had an unflinching dedication to fighting injustice.
To flinch is to pull away in fear or pain. If you don't flinch while your dad pulls a splinter out of your finger, you're unflinching. This means that you're resolute and unwavering, despite the fact that you may be dealing with something scary (or in this case, painful). Other things are figuratively unflinching, like your unflinching honesty, even in the face of a hostile reaction to what you say.