plumptitude
/ˈplʌm(p)tɪtjuːd/ /ˈplʌm(p)tɪtʃuːd/originally and chiefly US humorous
noun
Plumpness.
Origin
Mid 19th century; earliest use found in Nathaniel Willis (1806–1867). From plump + -itude, with epenthetic -t- after nouns ending in -(p)titude.