Sweet, perky, or youthful.
Tasting like bubblegum.
A type of pop music marked by sweetness, pep and charm (rather than depth or complexity).
A light pink colour, like bubblegum.
A sweet chewing gum formulated to be stretchy so the chewer can blow bubbles with it.
Easy, now especially in a disparaging sense; contemptibly easy.
Lazy, simplistic (especially of explanations, discussions etc.).
Effortless, fluent (of work, abilities etc.).
Of a reaction or other process, taking place readily.