emphasis If you describe something as excruciating, you are emphasizing that it is extremely painful, either physically or emotionally. I was in excruciating pain and one leg wouldn't move = unbearable + excruciatingly ex·cru·ci·at·ing·ly He found the transition to boarding school excruciatingly painful
If you describe something as excruciating, you mean that it is very unpleasant to experience, for example because it is very boring or embarrassing. Meanwhile, the boredom is excruciating There was a moment of excruciating silence. + excruciatingly ex·cru·ci·at·ing·ly The dialogue is excruciatingly embarrassing