A working hypothesis is an essential tool for scientists and researchers, as it provides a tentative explanation for a phenomenon or problem. However, in order to avoid repetition and maintain clarity, it's helpful to have a variety of synonyms at hand. Some possible alternatives include tentative hypothesis, preliminary theory, conjecture, supposition, postulate, premise, suggestion, thesis, and assumption. Each of these terms conveys a slightly different nuance of meaning, but all refer to a hypothesis that is still subject to further testing and refinement. Choosing the right synonym can help writers communicate their ideas effectively and concisely, while also enhancing the overall quality of their research.