1. Walking, standing, sitting, and lying down. 2. A shorthand way of referring to every conceivable mode of human activity. 3. "Always," i.e., whatever one is doing, twenty-four hours a day. 4. The proper deportment (igi 威儀) that Buddhist monks and nuns should adhere to in all of their activities.
Four Universal Vows (shigu seigan 四弘誓願). ☞ "Verse of Four Universal Vows."