The expression "be nothing like" is used to compare two things that are very different from each other. To convey the same meaning, there are several alternative phrases and synonyms that you could use. For instance, you could say "have nothing in common with," or "barely resemble." Other suitable synonyms could include "dissimilar," "opposite," "incompatible," "contrasting," or "divergent." All of these phrases express the idea of a significant difference or contrast between two things, characteristics, or actions. When writing, it's always helpful to have varied vocabulary to make your writing more interesting, engaging, and effective.