Transient! I think that’s the initial chaotic moment name I was looking. I can’t find any record of having researched it in the last seven years. Danced all around it but never saw it.
A nice definition from Quora:
“ When a system is disturbed from its equilibrium state, then the gap between the start of distortion in output and the time of attaining equilibrium is the period of instability. This instability is known as a transient. they are mostly prevalent in case of control systems.”