Complete, serene happiness.
Complete, serene happiness — perfect felicity, often with a spiritual or otherworldly completeness.
The calm, still, fulfilled pole of the family: perfect happiness rather than excited arousal, leaning toward paradise, heaven, and nirvana (“wedded bliss,” “eternal bliss,” “sheer bliss”). Settled and serene where exhilaration is adrenaline and euphoria a possibly precarious high; quiet and inward where jubilation is a public display; restful felicity rather than the transported trance of ecstasy or rapture. Close to contentment but more intense and complete (“ignorance is bliss,” “follow your bliss”).
Old English blis, bliðs “bliss, merriment, happiness, grace,” from Proto-Germanic, related to blithe “gentle, kind” — not to any “carry” root. Influenced by the unrelated word bless.
From mostly earthly happiness in Old English to “perfect felicity, the joy of heaven” already in late Old English, a sense that persists. A documented recent development: the U.S. colloquial verb “bliss out” (c. 1973).