1. A thin skin or membrane.
2. A thin, opaque, abnormal coating on the cornea of the eye.
3. A thin covering or coating: a film of dust on the piano.
4. A thin, flexible, transparent sheet, as of plastic, used in wrapping or packaging.
5. 1. A thin sheet or strip of flexible material, such as a cellulose derivative or a thermoplastic resin, coated with a photosensitive emulsion and used to make photographic negatives or transparencies.
   2. A thin sheet or strip of developed photographic negatives or transparencies.
6. 1. A movie.
   2. Movies considered as a group.
7. A coating of magnetic alloys on glass used in manufacturing computer storage devices.

1. To cover with or as if with a film.
2. To make a movie of or based on: film a rocket launch; film a scene from a ballet.

1. To become coated or obscured with or as if with a film: The window filmed over with moisture.
2. To make or shoot scenes for a movie.

[Middle English, from Old English filmen.]

WORD HISTORY   One indication of the gulf between us and our Victorian predecessors is that the Oxford English Dictionary fascicle containing the word film, published in 1896, does not have the sense "a motion picture." The one hint of the future to be found among still familiar older senses of the word, such as "a thin skin or membranous coating" or "an abnormal thin coating on the cornea," is the sense of film used in photography, a sense referring to a coating of material, such as gelatin, that could substitute for a photographic plate or be used on a plate or on photographic paper. Thus a word that has been with us since Old English times took on this new use, first recorded in 1845, which has since developed and now refers to an art form, a sense first recorded in 1920.

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.