https://www.military.com/join-armed-forces/military-terms-and-jargon.html
https://sierrahotel.net/pages/aviation-slang-pilot-slang
Also, these, if you need them.
It can, since the age of the gods is when everything was insanely powerful. But it can also literally just mean that their skill is something the Throne of Heroes sees as being immeasurable