まるまる丸々marumaru
1.

Describes something that is distinctly round or circular in shape, conveying a sense of fullness or completeness.

2.

Refers to a state of being noticeably robust or well-rounded, often used to describe a person's physique or appearance with an affectionate connotation.

3.

Implies an all-encompassing or total quality, suggesting something that is complete or fully realized in relation to a certain context or duration.

Example:

それから、毎日おじいさんと、おばあさんがこねこにミルクを飲ませましたら、こねこは、まもなく、かわいらしいまるまるとしたねこに、なりました。