# Does a hypothesis in science mean a tentative guess?

If you like. I would prefer $\text{an explanation consistent with the data.}$
An $\text{hypothesis}$ is a proposed explanation for a phenomenon. The hypothesis may be wrong or right; the hypothesis is $\text{scientific}$ if it is $\text{testable}$.
$\text{Testability}$ is the hallmark of a scientific hypothesis. The hypothesis may be wrong or right, but in order to be scientific, it must be $\text{testable}$. That is, we can do further experiments to test the accuracy of the hypothesis, and such tests lead to clear results that allows confirmation or rejection of the original hypothesis.