bug out

Meanings

1. To leave (a place) hastily.
2. To abandon someone without warning.
3. To miss school, play truant, play hooky.
4. To leave civilization to live off the grid; to escape an apocalypse or emergency by leaving the area.
5. To cause to bulge.
6. To bulge; to protrude.
7. To freak out, to go crazy, e.g. from worry.
8. To crash or glitch.

1. A rapid retreat, a rout.

Etymology

Attested 1950, popularized in the Korean War (1950–53) in such phrases as “bug-out fever” (rout) and “the big bug out” (November/December 1950 retreat) and entered civilian slang by mid 1950s. Likely originated in World War II, perhaps based on 1930s cartoons featuring bugs fleeing an impending foot or boot. Ultimately based on the rapid, disorderly flight of bugs when discovered, particularly their scattering if several are discovered at once, such as under a rock or can. Compare chicken out.