The phrase "be stirring" means to be active, moving around, or causing movement. There are several synonyms that can be used instead of this phrase, such as "stir", "move", "shift", or "rouse". Other synonyms that are similar in meaning include "agitate", "animate", "stir up", "arouse", "kindle", and "enliven". These words can be used in a variety of contexts, such as to describe physical movement, emotional stimulation, or inspiration to action. Whatever the situation may be, the use of these synonyms can add variety and depth to one's language and communication skills.