stringent
adj.very strict and precise. You use this to describe rules, laws, or tests that must be followed exactly and are hard to pass.
adj.imposing rigorous standards or requirements; precise and exacting. Often describes regulations, safety protocols, or financial controls.
“The airline has stringent safety rules.”
“To ensure public safety, the government introduced stringent new laws regarding chemical waste disposal.”
“The university maintains stringent entry requirements to ensure that only the most dedicated students are admitted to its prestigious medical program.”
Typically used attributively before a noun or predicatively after a linking verb like 'be' or 'become'.
Usage stringent criterion
“Also, human trials require stringent protocols and take years to start and complete.”
“There were stringent conditions for the pilot and the crew.”
Learned borrowing from Latin stringēns, stringentem, from Proto-Indo-European *streyg- (“to stroke, to shear, stiff”).
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.