The word Chonchito is often referred as a nickname for somebody that might be graciously chunky like a little piglet.
Chonchito is use in an affectionate way.
One case for example is the Chihuahua dog featured in this site name Chonchito, because when he was little he was as cute as a little piglet.
The origin of the word is from the Spanish language and other variations with the same meaning are the words, Chonchi, Lechonsito and Chanchito.