bliss 
(blĭs)
(blĭs)n.
Phrasal Verb: 1. Extreme happiness; ecstasy.
2. The ecstasy of salvation; spiritual joy.
bliss out Slang
To go into a state of ecstasy.
[Middle English blisse, from Old English bliss, from blīths, from blīthe, joyful; see BLITHE.]
blissful adj.
blissful·ly adv.
blissful·ness n.