bless

Etymology 1

From Middle English blessen, from Old English bletsian (“to consecrate (with blood)”), from Proto-West Germanic *blōdisōn (“to sprinkle, mark or hallow with blood”), from Proto-Germanic *blōþą (“blood”), of uncertain origin, possibly from Proto-Indo-European *bʰleh₃- (“to bloom”). Cognate with Old Norse bleza (“to bless”) (whence Icelandic blessa), Old English blēdan (“to bleed”). More at bleed.

verb

1. To make something holy by religious rite, sanctify.
2. To make the sign of the cross upon, so as to sanctify.
3. To invoke divine favor upon.
4. To honor as holy, glorify; to extol for excellence.
5. To esteem or account happy; to felicitate.
6. (obsolete) To wave; to brandish.
7. (Perl programming, transitive, past tense only blessed) To turn (a reference) into an object.
8. (archaic, with from) To secure, defend, or prevent from.

Etymology 2

An ellipsis for an expression such as bless your heart.

intj

1. (UK, Canada, informal) Used as an expression of endearment, gratitude, or (ironically) belittlement.
   Ah bless! You must be the welcoming committee for anyone who dares express ignorance. 1998, Peter Coffey, “New Alternative View Of Atomic Structure”, in sci.chem (Usenet)
   oh bless. *hug* that is not true. nobody here bears a grudge against 13 year old dear or against you. 2000, Hellraiser, uk.people.teens (Usenet)
   Aw bless... have white chocolate fudge muffin....a new batch.... made them last night after Nigella.... 2001, Will, “Am I still here?”, in uk.religion.pagan (Usenet)