What is the meaning of Bless?

To make something holy by religious rite, sanctify.

To make the sign of the cross upon, so as to sanctify.

To invoke divine favor upon.

To honor as holy, glorify; to extol for excellence.

To esteem or account happy; to felicitate.

To wave; to brandish.

To turn (a reference) into an object.

To secure, defend, or prevent from.

To give or send.

To approve of or assent to.

To perform the mano gesture; taking of an elder's hand to press it to one's forehead or kiss it

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Used as an expression of endearment, gratitude, or (ironically) belittlement.

goodbye, bye

to bless

Source: wiktionary.org