be absent without leave

To not be present for one's duty or a particular situation without permission. The phrase is usually used in reference to military service, and it is often abbreviated as the acronym "AWOL." The young soldier was arrested for being absent without leave. Jackie, you were absent without leave during our busiest period of the year. You're fired. The boss thought I was absent without leave because I was too sick to call in and say that I needed to miss a day of work.