Elastance is a term used in mechanical engineering and physiology to describe the measure of an object's ability to resist deformations due to applied forces. This term is often used interchangeably with "elasticity," "stiffness," and "resilience." In the context of physiology, elastance refers to the measure of lung function, specifically how much pressure is required to inflate the lungs. Other synonyms for elastance include "compliance," "distensibility," and "flexibility." These terms are all components of measuring an object's elasticity and are crucial for understanding the mechanical and physiological functions of various materials, structures and systems.