The phrase "having up tree" commonly refers to the act of climbing up a tree. There are several synonyms that can be used to describe this action. Some of these synonyms include "ascend," "scale," "clamber," "scale," and "climb up." Each of these synonyms can be used in different contexts to convey a slightly different meaning or idea. For example, "ascend" may be used to describe a more deliberate and controlled climb, while "clamber" might be used to describe a more hasty or frantic climb. Regardless of the synonym used, the phrase "having up tree" implies a sense of adventure and excitement.