Roof n.
 1. Arch. The cover of any building, including the roofing (see Roofing) and all the materials and construction necessary to carry and maintain the same upon the walls or other uprights. In the case of a building with vaulted ceilings protected by an outer roof, some writers call the vault the roof, and the outer protection the roof mask. It is better, however, to consider the vault as the ceiling only, in cases where it has farther covering.
 2. That which resembles, or corresponds to, the covering or the ceiling of a house; as, the roof of a cavern; the roof of the mouth.
 The flowery roof
 Showered roses, which the morn repaired.   --Milton.
 3. Mining. The surface or bed of rock immediately overlying a bed of coal or a flat vein.
 Bell roof, French roof, etc. Arch. See under Bell, French, etc.
 Flat roof. Arch. (a) A roof actually horizontal and level, as in some Oriental buildings. (b) A roof nearly horizontal, constructed of such material as allows the water to run off freely from a very slight inclination.
 Roof plate. Arch. See Plate, n., 10.


 French prop. a.  Of or pertaining to France or its inhabitants.
  French bean Bot., the common kidney bean (Phaseolus vulgaris).
 French berry Bot., the berry of a species of buckthorn (Rhamnus catharticus), which affords a saffron, green or purple pigment.
 French casement Arch. See French window, under Window.
 French chalk Min., a variety of granular talc; -- used for drawing lines on cloth, etc. See under Chalk.
 French cowslip Bot. The Primula Auricula. See Bear's-ear.
 French fake Naut., a mode of coiling a rope by running it backward and forward in parallel bends, so that it may run freely.
 French honeysuckle Bot. a plant of the genus Hedysarum (H. coronarium); -- called also garland honeysuckle.
 French horn, a metallic wind instrument, consisting of a long tube twisted into circular folds and gradually expanding from the mouthpiece to the end at which the sound issues; -- called in France cor de chasse.
 French leave, an informal, hasty, or secret departure; esp., the leaving a place without paying one's debts.
 French pie [French (here used in sense of “foreign”) + pie a magpie (in allusion to its black and white color)] Zool., the European great spotted woodpecker (Dryobstes major); -- called also wood pie.
 French polish. (a) A preparation for the surface of woodwork, consisting of gums dissolved in alcohol, either shellac alone, or shellac with other gums added. (b) The glossy surface produced by the application of the above.
 French purple, a dyestuff obtained from lichens and used for coloring woolen and silken fabrics, without the aid of mordants. --Ure.
 French red rouge.
 French rice, amelcorn.
 French roof Arch., a modified form of mansard roof having a nearly flat deck for the upper slope.
 French tub, a dyer's mixture of protochloride of tin and logwood; -- called also plum tub. --Ure.
 French window. See under Window.


 French roof
      n : a mansard roof with sides that are nearly perpendicular