The term "tax hike" is a widely used phrase to describe an increase in taxes. However, there are various synonyms that can be used to describe this phenomenon. For instance, "tax increase" is a simple and straightforward alternative to "tax hike". Another option is "tax uptick", which implies a minor increase. "Tax boost" is also appropriate when referring to an increase in taxes that is aimed at boosting government revenue. "Tax surge" is another synonym that can be used to describe a sudden and significant increase in taxes. Finally, "tax jump" suggests a sudden and substantial increase in taxes, while "tax spike" implies a sharp and brief increase in taxes.