This word was chosen in Old English bibles to translate Latin benedicere and Greek eulogein, both of which have a ground sense of "to speak well of, to praise," but were used in Scripture to translate Hebrew brk "to bend (the knee), worship, praise, invoke blessings." L.R. Palmer ("The Latin Language") writes, "There is nothing surprising in the semantic development of a word denoting originally a special ritual act into the more generalized meanings to 'sacrifice,' 'worship,' 'bless,' " and he compares Latin immolare (see immolate).
The meaning shifted in late Old English toward "pronounce or make happy, prosperous, or fortunate" by resemblance to unrelated bliss. Meaning "invoke or pronounce God's blessing upon" is from early 14c. No cognates in other languages. Related: Blessed; blessing.
"to cross oneself; to mark or bless with the sign of the cross," Old English segnian, from Latin signare "to sign, mark, distinguish" (in Church Latin and Medieval Latin "to make the sign of the Cross"); see sign (n.). A common Germanic borrowing, cognate with Old Saxon segnon, Dutch zegenen, Old High German seganon, German segnen "to bless," Old Norse signa. Century Dictionary (1889) marks it "Obsolete or Scotch."
1914, from German Gesundheit, literally "health!", from Old High German gisunt, gisunti "healthy" (see sound (adj.)). Also in the German toast auf ihre Gesundheit "to your health." God bless you after someone sneezes is credited to St. Gregory the Great, but the pagan Romans (Absit omen) and Greeks had similar customs.
in Irish and pseudo-Irish expressions, by 1829, from Irish-Gaelic mo chroidhe "(of) my heart," hence "my dear!" The once-popular song "Mother Machree" ("I kiss the dear fingers so toil worn for me. Oh God bless you and keep you, Mother Machree") was written in 1910, popularized by John McCormack (1911) and other Irish tenors.
1530s, "to make very happy," from French béatifer, from Late Latin beatificare "make happy, make blessed," from Latin beatus "supremely happy, blessed" (past participle of beare "make happy, bless;" see Beatrice) + -ficare, combining form of facere "to make" (from PIE root *dhe- "to set, put"). The Roman Catholic Church sense of "to pronounce as being in heavenly bliss" (1620s) is the first step toward canonization. Related: Beatified; beatifying.