I think the term spiritual is nonsense. A better term would be engaged. If you are helping others in ways that you can or if you look out for others or if you see beauty in nature or within people you are said to be spiritual. I believe you are tuned into life. John Donne said "No man is an island and Thoreau said, "It's not what you look at that matters, its what you see."

Remember that atheism only means no God belief.

I have no clue and often ask people what the hell they mean by that term.
I find that most mean some form of Human emotion, Compassion, Love, Integrity, some aspect of character and emotion, mixed together in a smoky fashion like an ether . . .
This is labled "spiritual" because it makes them feel good in one way or another, so certain emotive states of mind are labeled thusly

Spirit means breath, so we do have it. But, I think of being spiritual as being in that mysterious place that feels higher, perhaps in the higher mind where we see people as we used to think that God did: everyone is worthy and special in some way, of merit to the whole of things. Spiritual growth is of the inner person, the plane above the selfish mundane.

In my frame of mind it means to recognize the conscience, to verify it. Then opens the world of our personal mind. Feeling the self and realizing the connection with all energy. Our atoms are 14 billion years old and are fully energized, They merely take on different relationships as time moves on. Spiritual is to be aware of this individual mind that talks to us and who the hell is us. Who are we talking to when we talk to ourselves, That is the spiritual world. Maybe someday we will actually discover it

The word 'spirit' was invented when some unknown bump in the night scared the wits out of our ancestors. It soon became associated with human form in fantasy explanations of cause. Human imagination developed it to high levels.

I still associate Spirit or spiritual with 'Unknown' . So spiritualism to me means they have had experience of something they cannot fully explain in scientific terms . It remains a human failing to shoot off into fantasy , but it does make life interesting.

no!

Fucked if I know

"Spiritual" has not a damn thing to do with religion.

Well, you'd have to ask the person in question. I expect people mean all sorts of things when they say "spiritual". From my perspective it means there are things they get emotional about and for some reason they think that's some sort of higher feeling.

I continue to be surprised that atheists, who have taken the time to figure out the lack of evidence for gods, continue to believe in other stuff for which there is no evidence.

Atheism is the rejection of the claim of god(s). Spirituality isn't a God.

It would seem to me that by definition, one would believe in a spiritual realm. A-theism is just one thing, "disbelief OR lack of belief [non-belief] in the existence of God or gods" and by that definition, one can be both A-theist and spiritual. You can believe in ghosts, demons, spirits, or anything supernatural you just do not believe in god(s). (In My Humble Opinion))