firm pink flesh at the base of the teeth
a hard transparent jelly-like sweet
sticky substance which oozes from certain trees, used for making glue
stick sth with sticky substance
"if you gum the tape it is stronger"
"the old man had no teeth left and mumbled his food"
"these trees gum in the Spring"
If you haven't got the special fasteners to fix your photographs into the book, you'll have to gum them on.