1. What does it mean?
Borrowing the image of a forceful straight pitch, 돌직구 describes a comment or question delivered very directly. The speaker goes straight to the point instead of hinting.
Also written or said as 돌직구를 던지다
2. The nuance
It can be praise for clarity or a complaint about tactlessness. Direct wording does not make a claim accurate, and a 돌직구 about someone else's appearance or private life can still be intrusive. The listener's reaction helps determine the tone.
3. Examples
“회의에서 그 일정은 불가능하다고 돌직구를 던졌어.”
In the meeting, I said outright that the schedule was impossible.
“왜 답장을 안 했냐는 돌직구 질문에 잠깐 당황했어.”
The blunt question about why I hadn't replied caught me off guard.
Sources
KoreanClass101: Korean language lessons
References support the meaning and usage. Example sentences are written for NoCapWiki.