When we say someone is "in full cry," it means they are fully engaged and enthusiastically pursuing a goal or activity. If you're looking for alternative phrases to express this same idea, there are several options available. For example, you might say someone is "fully immersed" in what they're doing or "fully committed" to a particular cause. Other options include "fully invested," "fully focused," or simply "going all out." Each of these phrases highlights the idea of someone giving their all to a task or mission, much like a hunting dog that is fully engaged in tracking its prey.