plump
Somewhat curvier bodies, without being fat, or at most borderline. A saying that goes around for plump is "Fat in all the right places".
The Japanese tags above are Pixiv's equivalent of the word, but be aware that not all Pixiv-centric uses of those tags fit Danbooru's definition. As with all other size-specific tags, observe the body and see if the tag actually needs to be used before adding it.
Yotsuba Satsuki from the series Mahou Sensei Negima! and Itou Yukino of Real Drive are examples of plump bodies.
See also
The following tags are aliased to this tag: chubby and muchi (learn more).