"Rigorous" Natural Recordings by Native Speakers
Severe or strict in demands or conditions; thorough and exhaustive in treatment or analysis; demanding great effort or thought.
Verb<br><br>To make or become stiff and unyielding, or to make something stiff and unyielding.<br><br>Example:<br>The doctor applied a specific cream to the muscle to rigidize it and prevent further injury.
Being or done exactly according to a set of rules or instructions, without any flexibility or changes.