This eigenfunction is one of the fundamental concepts of quantum mechanics.

My boat is equipped with the latest fishfinder.

He found a way to profit from a difficult situation like fishing at the bottom of a river.

His ability is underestimated.

You should not underestimate his ability.

I think his abilities are overestimated.

He is overestimating his own abilities.

He was swimming freely as if he was a fish playing in the pot.

He is a person who follows his own path, and the phrase 'a big fish does not swim into a small stream' fits him perfectly.

His variety of pitches is very diverse, which troubles the batters.