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.
Wiktionary(5.00 / 1 vote)Rate this definition: tension(Noun) Psychological state of being tense. tension(Noun) Condition of being held in a state between two or more forces, which are acting in opposition to each other. tension(Noun) State of an elastic object which is stretched in a way which increases its length.