envelope vs film

envelope

noun
  • An enclosing structure or cover, such as a membrane; a space between two membranes 

  • Something that envelops; a wrapping. 

  • A curve that bounds another curve or set of curves, as the modulation envelope of an amplitude-modulated carrier wave in electronics. 

  • A mathematical curve, surface, or higher-dimensional object that is the tangent to a given family of lines, curves, surfaces, or higher-dimensional objects. 

  • A paper or cardboard wrapper used to enclose small, flat items, especially letters, for mailing. 

  • The nebulous covering of the head or nucleus of a comet; a coma. 

  • The set of limitations within which a technological system can perform safely and effectively. 

  • The shape of a sound, which may be controlled by a synthesizer or sampler. 

  • The information used for routing a message that is transmitted with the message but not part of its contents. 

  • An earthwork in the form of a single parapet or a small rampart, sometimes raised in the ditch and sometimes beyond it. 

  • A bag containing the lifting gas of a balloon or airship; fabric that encloses the gas-bags of an airship. 

film

noun
  • A thin layer of some substance; a pellicle; a membranous covering, causing opacity. 

  • A medium used to capture images in a camera. 

  • A slender thread, such as that of a cobweb. 

  • A visual art form that consists of a sequence of still images preserved on a recording medium to give the illusion of motion; movies generally. 

verb
  • To cover or become covered with a thin skin or pellicle. 

  • To visually record (activity, or a motion picture) in general, with or without sound. 

  • To record (activity, or a motion picture) on photographic film. 

How often have the words envelope and film occurred in a corpus of books? (source: Google Ngram Viewer )