> At first glance, I thought "Gum is food, it goes in your mouth." Then I checked in a dictionary...
>
> chewing gum
> n
> A sweetened and flavored insoluble plastic material (as in a preparation of chicle) used for chewing.
>
> note that chewing gum is that preparation of chicle (which is itself made from latex, yuck). The definition also didn't say "food", but "plastic material" and "preparation". Plus, it's latex! Do any of you eat rubber gloves and balloons?

Perhaps you should look up "latex" and "plastic" in a dictionary. "Plastic" doesn't necessarily mean "made of plastic". Saying a substance is plastic refers to it being impressionable, bendy, squidgy, stretchy and so forth. Likewise, latex is a term for the sap of certain plants, as well as being a particular artificially created substance. Chicle is made from the sap (latex) of one such plant.