거침없이 말하다/나아가다 · 거침없다 (adj.)
without hesitation, freely, smoothly; unstoppably
Example
그 학생은 어려운 질문에도 거침없이 대답했어요.
That student answered without hesitation, even to the hard questions.
Word parts
From 거치다 'to get snagged' — literally 'without catching on anything'.