All 5 Uses of

pious
in
Treasure Island

"Now, for instance, you wouldn't think I had had a pious mother—to look at me?" he asked.
Chpt 15

pious = highly religious and moral

And I was a civil, pious boy, and could rattle off my catechism that fast, as you couldn't tell one word from another.
Chpt 15

That's what it begun with, but it went further'n that; and so my mother told me, and predicked the whole, she did, the pious woman!
Chpt 15

I've thought it all out in this here lonely island, and I'm back on piety. ... I'm bound I'll be good, and I see the way to.
Chpt 15 *

piety = highly moral behavior

Definitions:

(1) (pious as in: a good, pious woman)
religious or highly moral
(2) (pious as in: a pious hypocrite)
self-righteous (acting as though one is, or believing one is highly moral when it is not true)
(3) (pious as in: cling to the pious hope)
(describing a hope or wish as) sincere, but highly unlikely
(4) (meaning too rare to warrant focus)
meaning too rare to warrant focus:

Much more rarely, piety can refer to devotion or faithfulness as Proust used it in the book, Swann's Way:

"...but when, as had befallen me, such an anguish possesses one's soul before Love has yet entered into one's life, then it must drift, awaiting Love's coming, vague and free, without precise attachment, at the disposal of one sentiment to-day, of another to-morrow, of filial piety or affection for a comrade."