The word "toughies" is often used to refer to difficult challenges or tasks that require a lot of effort to overcome. However, there are many other synonyms that can be used to describe these kinds of situations. Some possible alternatives include "challenges," "difficulties," "obstacles," "hardships," and "problems." Each of these words conveys a slightly different nuance or emphasis, so choosing the right synonym can help to convey the precise meaning you intend. By using synonyms, you can add variety and depth to your writing, and convey your ideas in a more nuanced and nuanced way.