When looking for synonyms for the word "more tough-nut", you can find a range of options that capture the same meaning of something that is difficult to solve or comprehend. Some of the most common synonyms include "challenging", "complicated", "complex", "intricate", and "problematic". These words all describe a situation or task that requires a high level of skill, attention, and effort to overcome. Other synonyms for "more tough-nut" include "daunting", "formidable", "hard", "strenuous", and "demanding". Whether you are trying to solve a challenging problem, tackle a difficult task, or overcome a complex obstacle, these synonyms can help you describe the situation at hand and express your feelings about it.