Probable error is a statistical term that indicates how much a measured value differs from the true value. If you're looking for synonyms for this term, you could consider using the phrases "margin of error," "confidence interval," or "standard error." These phrases all describe the degree of uncertainty associated with a certain measurement or calculation. Other options might include "uncertainty range," "precision error," or "measurement error." Whatever term you choose to use, it's important to understand that all measurements come with a certain level of uncertainty, and it's critical to factor in this uncertainty when making decisions or drawing conclusions based on data.