Shorter version of "My God".
Not to be confused with OMG.
It's usage is closer to "Great Scott", "Jeez", or "By the beard of Zeus"
A: "Dude, have you seen the new Star Wars Trailer?"
B: "Migad! It's beautiful!"
2020 Presidential Debate, the three old white men arguing with each other.
Meaningless sounds in the background that you unintentionally ignore or intentionally pretend to not exist.
"Sorry for the white noise. I didn't notice I left the TV on."
"No that's fine. It helped me fall asleep."