Gumming is a disease which attacks the vine, plum, peach, cherry and other trees. It is very contagious, and is due to a fungus, Coryneum Beijerinckii, which converts the cell-walls and contents into gum, as in the production of gum arabic. Found on http://www.probertencyclopaedia.com/browse/BGA.HTM
In offset lithography, an operation which is intended to spread a thin gum dried film on the surface of non-image areas to avoid oxidation by oxygen in the air. Found on https://www.xrite.com/learning/other-resources/glossary