1. Resin obtained from various conifers. 2. A black or dark viscous substance obtained as a residue in distilling tar or oil from bones; it also occurs in natural form as asphalt. 3. The slope of a stairway, in degrees. 4. The slope of a roof. 5. Degree of slope or grade given a horizontal run of pipe. 6. The spacing of rivets or bolts. 7. The frequency of sound vibrations. 8. In carpet, the number of pile ends per inch of width; actually, in practical floor covering specifications, it is taken as the number of pile ends per unit of standard 27-inch width; terms of pitch used commonly in the industry are 180, 189, 192, 216 and 256.