1. deal with a difficult situation in a direct and courageous way
take/grab the bull by the horns and get something done
Bulls are dangerous animals, so no one in their right mind would grab one by its horns! When you use this expression, you are declaring that the task ahead is difficult and you are determined to see it through. People sometimes use this when they have been procrastinating (avoiding a task) and they have chosen to motivate themselves. Although this is used in social situations, you are more likely to hear it in professional contexts.