exigent

This term carries a high degree of formality and is most frequently encountered in legal, medical, or administrative contexts. It describes a state of pressing necessity where the window for action is narrow, creating a sense of acute pressure. While it overlaps with urgent, it suggests a more systemic or structural requirement for immediate response rather than just a feeling of haste.

When applied to a person's character, the word shifts from temporal urgency to a demand for rigor. In this sense, it describes someone who is exacting or stringent, often to the point of being taxing. This usage implies a standard of perfection that is relentlessly pursued, distinguishing it from simple strictness by emphasizing the exhaustive nature of the demands placed on others.