Density links mass with volume. Density=mass/volume, so mass=volume×density.
An object with a given constant cross-sectional area (such as a wire or block of wood) can be assigned a line density, so mass=volume×(line density).
So you need the density and dimensions of the object to find the mass; or the line density and length.
If the object is a 1-foot length of wire with line density of 2 ounces per foot then its mass=2 ounces or ⅛lb.