When you have a toddler who is round and plump, this is an example of someone who would be described as chubby.
It's quite normal for healthy babies to have chubby cheeks.
A chubby baby.
Origin of chubby
- Probably from chub (from the plumpness of the fish)
From American Heritage Dictionary of the English Language, 5th Edition
- recorded since 1611, from chub (short, thick fish species, used as bait), used metaphorically for "lazy person" since 1558; perhaps influenced by Old Norse kumba "log" and/or kumben "stumpy."