Discussion Forum—A Way with Words, a fun radio show and podcast about language

A revelation is when something is revealed; it usually means you realize something (or someone explains something) that you didn't know before.   Nowadays we use it to mean something surprising or of great consequence.

The original "epiphany" is an event in the New Testament, also called the "transfiguration"; it's when Jesus, up on a mountain with three of his disciples, seemed to become blindingly bright, and Moses and Elijah appeared and talked with him.   It's called the "transfiguration" because his figure (ie his appearance) was changed; it's called the "epiphany" because his appearance temporarily matched his true nature, so that his disciples saw plainly who he is.   Nowadays, we say "epiphany" to mean any great revelation, I suppose, though someone else here may use it in a narrower sense.

So to answer your question, I would say that "revelation" and "epiphany" do not mean "peaceful", and neither word means "abysmal"; they're just events where you realize something important and possibly even life-changing.   Could be good, could be bad.

Although usually I think any new understanding, if true, is a good thing, even if it's unwelcome at the time.   If a mother in one of those crime dramas on TV comes to realize that her son is a murderer, it's a revelation even if it's a sad one.   But it's better that she know than that she remain ignorant.   Likewise, say you're in love with a woman but you believe she doesn't like you very much; if she says something that causes you to realize that she's in love with you, too, it's a revelation—a good one (a very good one).

Come to think of it, I reserve the word "epiphany" for when I realize something more fundamental than that.   If I think of myself as a basically moral man, and then my eyes are somehow opened to an area of my life where I've been behaving immorally all my life, I would call that an epiphany; it changes my view of myself.   Of course epiphanies can be good too.

Oh, I see; I misread your post, Rafee.   I thought you were asking about the meaning of "revelation" or "epiphany"; but you're asking about what adjective means something like them in the phrase "an <adjective> moment".   Sorry.   "Pivotal" sounds good to me, but then you wouldn't have mistaken it for "peaceful"...nor for "abysmal", I guess.   Nothing better comes to me, though.