A few butterflies and many moth species spin a silk case or cocoon prior to pupating, while others do not, instead going underground. A butterfly pupa, called a chrysalis, has a hard skin, usually with no cocoon.
4. tension - (physics) a stress that produces an elongation of an elastic physical body; the direction of maximum tension moves asymptotically toward the direction of the shear. natural philosophy, physics-the science of matter and energy and their interactions; his favorite subject was physics.
Princeton's WordNet(4.75 / 4 votes)Rate this definition: tension, tenseness, stress(noun) (psychology) a state of mental or emotional strain or suspense. he suffered from fatigue and emotional tension; stress is a vasoconstrictor. tension, tensity, tenseness, tautness(noun) the physical condition of being stretched or strained.