Fingerbreadth is a word that typically refers to the width of a finger, especially the thumb. However, there are some other synonyms that could be used in place of this term. For example, some people might use the term "digit" to refer to the width of a finger. Others might use the term "inch" or "centimeter" to describe a similar measurement. Additionally, some people might use descriptive terms such as "narrow" or "slender" to describe something that is roughly the width of a finger. Ultimately, there are many different ways to describe this measurement, and the best choice will depend on the specific context in which it is being used.