(idiomatic) Being taken care of or being addressed.
Don't worry; the police have been called and the situation is under control.
(literally) Being actively controlled, or able to be actively controlled in its current state.
Throughout the turbulence encounter, the pilots kept the aircraft under control.
The control rods absorb neutrons in the reactor core, keeping the fission reaction under control and preventing it from going prompt critical.
Honesty is a good thing, but it is not profitable to its possessor unless it is kept under control. Don Marquis
My attitude on skis is different now. I have learned to put less pressure on myself and on the edges of my skis when I'm racing, to be keep myself more under control. Hermann Maier
My worst vice is gluttony. I try to keep myself under control because I'm an athlete, but once a week I like to pig out and act like a normal person. Gianluigi Buffon
But, what we need to get out of the first EVA is to have the arm completely unfolded and powered so that they can keep the temperature under control. That will really the call of the first EVA. Umberto Guidoni
What you feel spiritually. I think a lot of that has to do with it. If you have no spiritual life, chances are everything is going to aggravate you, you're going to fly off the handle at everything and that's what I did in the past. I've kind of got that under control now. Mike Ditka
A fool gives full vent to his anger, but a wise man keeps himself under control. Italian Proverb