Elastic, resilient, springy, flexible, supple are comparable when they mean able to endure strain (as extension, compression, twisting, or bending) without being permanently affected or injured.
Elastic and resilient are both general and scientific terms; the scientific senses are later and are in part derived from the earlier meanings.
Elastic in nontechnical use is applied chiefly to substances or materials that are easy to stretch or expand and that quickly recover their shape or size when the pressure is removed.
In scientific use elastic is applicable to a solid that may be changed in volume or shape, or to a fluid (gas or liquid) that may be changed in volume, when in the course of the deformation of such a solid or fluid forces come into play which tend to make it recover its original volume or shape once the deforming force or forces are removed.
The term in such use describes a property (elasticity ) which a substance possesses up to the point (the elastic limit ) beyond which it cannot be deformed without permanent injury.
Resilient in nontechnical use is applicable to whatever springs back into place or into shape especially after compression; thus, rising bread dough is said to be resilient because it quickly recovers from a deforming pressure by the hand; a tree’s branch may be described as resilient when it snaps back into its former position once a pull is released.
Scientifically, resilient is not the equivalent of elastic, but it may be used as its counterpart; elastic stresses the capacity for deformation without permanent injury, resilient the capacity for recovering shape or position after strain or pressure has been removed; thus, when an elastic substance is stretched or compressed, it shows itself resilient ; as arteries gradually become less elastic with age, to the same extent they become less resilient.
Springy is a nontechnical term that carries the meanings and suggestions of both elastic and resilient and stresses at once the ease with which a thing yields to pressure or strain and the quickness of its return.
Flexible is applicable to whatever can be bent or turned without breaking; the term may or may not imply resiliency, or quick recovery of shape.
Supple applies to things which are, in general, not as solid or firm in structure as some which may be described as flexible; it also implies ease in bending, twisting, or folding or flexing, together with resistance to accompanying injury (as from breaking, cracking, or splitting).
In extended use these words often carry the implications of their literal senses.
Elastic stresses ease in stretching or expanding beyond the normal or appointed limits.
Resilient implies a tendency to rebound or recover quickly (as in health or spirits) especially after subjection to stress or strain (see ELASTIC 2 ).
Springy, which is less common in extended use, may suggest youth, freshness, or buoyancy.
Flexible implies an adaptable or accommodating quality or, when applied to persons, pliancy or tractability.
Supple, in its extended use, is applied chiefly to persons or their utterances. Sometimes it suggests little more than flexibility; at other times it implies obsequiousness or complaisance or a show of these with what is actually astute mastery of a situation.