na-adjective, noun
richer than it appears; secretly wealthy
Describes a person or household that is actually well-off despite an outwardly modest or frugal appearance. Often used in the phrase 内福な人.
彼はいつも質素な服を着ているが、実は内福なんだ。
He always wears simple clothes, but he's actually secretly wealthy.
あの家は内福で、見かけによらず裕福だ。
That family is richer than it looks; they are well-off despite appearances.