early 13c., from Old French forme "physical form, appearance, pleasing looks; shape, image," from Latin forma "form, contour, figure, shape; appearance, looks' model, pattern, design; sort, kind condition," origin unknown. One theory holds that it is from Greek morphe "form, beauty, outward appearance" (see Morpheus) via Etruscan [Klein]. Sense of "behavior" is first recorded late 14c. Meaning "a document with blanks to be filled in" is from 1855.