<p><strong>Noun</strong></p><ul><li>A flat paper container, as for a letter or thin package, usually having a gummed flap or other means of closure.</li><li>Something that envelops; a wrapper, integument, or surrounding cover.</li><li>Biology: A surrounding or enclosing structure, as a corolla or an outer membrane.</li><li>Geometry: A curve or surface tangent to each member of a set of curves or surfaces.</li><li>Radio: (of a modulated carrier wave) A curve connecting the peaks of a graph of the instantaneous value of the electric or magnetic component of the carrier wave as a function of time.</li><li>The fabric structure enclosing the gasbag of an aerostat.</li><li>The gasbag itself.</li><li>Electronics: The airtight glass or metal housing of a vacuum tube.</li><li>The technical limits within which an aircraft or electronic system may be safely operated.</li></ul><p><strong>End of Response</strong></p>