Gum and Rosin

Gum noun - Any of various substances (soluble in water) that exude from certain plants; they are gelatinous when moist but harden on drying.

Rosin and gum are semantically related. in sticky substance topic. In some cases you can use "Rosin" instead a noun "Gum".

Rosin noun - Any of a class of solid or semisolid viscous substances obtained either as exudations from certain plants or prepared by polymerization of simple molecules.

Gum and rosin are semantically related. You can use "Gum" instead a noun "Rosin".