καθεύδω

G2518 means to sleep. Its twenty-two forms occur in twenty verses across five books. Some uses describe ordinary physical sleep: Jesus sleeps during the storm, people sleep while an enemy sows weeds, and the bridesmaids sleep while the bridegroom is delayed. Other passages use sleep within a death scene, as when Jesus says that Jairus' daughter is asleep before raising her. Gethsemane and watchfulness passages set sleeping against prayerful alertness. Ephesians calls a sleeper to awake and rise from the dead, while 1 Thessalonians contrasts sleep with spiritual watchfulness and sobriety.

The same verb therefore serves literal rest, narrative description, death-related speech, failed vigilance, and moral exhortation. Those senses must not be collapsed. Ordinary bodily sleep is a creaturely good and is not automatically spiritual indifference. Jesus' words about the girl do not deny that the mourners understood her to be dead; the narrative displays His authority over the situation. In 1 Thessalonians 5:10, awake or asleep is best handled with humility because interpreters relate it either to vigilance and sleep or to life and death within the surrounding argument. The passage's assurance that believers live together with Christ remains central.

G2518 ranges from ordinary sleep to death-related language and exhortations to vigilance. The actor, scene, contrast, and surrounding argument determine its force.