1. What does it mean?
칼퇴 shortens 칼같이 퇴근, clocking out with knife-like precision. It means finishing work and leaving on time rather than staying late. The sharpness refers to timing, not hostility.
Also written or said as kaltoe
2. The nuance
It does not mean sneaking out early or neglecting a task. It is casual office language; 정시 퇴근 is the more neutral expression.
3. Examples
“오늘은 약속이 있어서 칼퇴할 예정이야.”
I have plans today, so I'm aiming to leave work right on time.
“업무를 미리 정리해 두니 칼퇴가 가능했어.”
Getting my work organized ahead of time let me leave on schedule.
Sources
References support the meaning and usage. Example sentences are written for NoCapWiki.