
"What is the lightest element on Earth
with no STABLE isotope?"
The Big Bang Theory Season 1, Episode 13

Well, he's never going to learn to fight
because he's a STABLE boy.
Game of Thrones Season 6, Episode 2

I don't understand.
He was STABLE.
Westworld Season 2, Episode 4

for synthesizing a new STABLE
super-heavy element?
The Big Bang Theory Season 7, Episode 6

Sons of your
father's bannermen, squires, STABLE boys?
Game of Thrones Season 3, Episode 6