- A yellow, water-soluble, gummy polysaccharide found in plant cell walls and yielding xylose upon hydrolysis.
- A gelasinous, levorotatory compound, C<sub>5</sub>H<sub>8</sub>-O<sub>4</sub>(?), contained in all kinds of wood. With sulphuric acid it yields the sugar xylose; boiling mineral acids convert it chiefly into fur-furaldehyde. It is also called <internalXref urlencoded="wood-gum">wood-gum</internalXref>.
- A gummy substance of the pentosan class, present in woody tissue, and yielding xylose on hydrolysis; wood gum.
- A <xref>polysaccharide</xref>, consisting of <xref>xylose</xref> residues, found in the cell walls of some algae and plants.