Britsh Army slang - To move away from your current location very qucickly (often under fire) becasue your position has been compromised by the enemy.

an act of freaking out over usually nothing; overreacting

while someones high, something happens that makes them nervous

To get out of an unsafe area
Some times associated with zombie apocalypse

was used in the early 1940's meaning to leave, to go,to travel somewhere

(Noun) bug out, Slang. to flee in panic; show panic or alarm .Someone or something that is feeling nervouse , paranoied, or inattentive,usually freaking out for no reason, overly dramatic or over exaguarting
(Verb)Someone or something that is doing that act of freaking out , acting upon paranoia.
Originated from the word Bug (noun)any insect or insectlike invertebrate,referring to the way an insect would appear,or act in movement, vibrations, indicating nervousness or Panic.

1. Any and all stimuli that could negatively affect the homeostatic balance of the human body in any way, such as a stressful situation, or possible threat, even a moderate change in temperature.

2. Something that is so highly profound and/or great in magnitude that you can fixate on it.

3. To abstain or leave a particular situation that is undesirable or perhaps even detrimental