gumming (Noun) — Ineffectual chewing (as if without teeth).
gumming (Verb) — Cover, fill, fix or smear with or as if with gum. ex. "if you gum the tape it is stronger"
gumming (Verb) — Grind with the gums; chew without teeth and with great difficulty. ex. "the old man had no teeth left and gummed his food"
gumming (Verb) — Become sticky.
gumming (Verb) — Exude or form gum. ex. "these trees gum in the spring"