[Haskell-cafe] What's the story behind "applicative" in "Constant Applicative Form"?

[sonne]

Hi cafe.

I've been trying to make the concept of CAFs get through to me, but
the very name is cryptic enough to stupefy me. What does it mean for a
thing to be "applicative"? Is it related to the concept of applicative
functor (likely not)? What would a constant non-applicative form look
like? A non-constant applicative form? An applicative non-form, in the
end?

I put a question on Stack Overflow about this, only to discover no
one's really sure. I would appreciate either an answer put there right
away or a permission to re-post or rephrase an answer there myself,
but, if you do mind, I will of course keep the answer private to this
mailing list. This is the link to the question:
stackoverflow.com/questions/48489778

Thank you!

P.S. I guess this is my first e-mail to this list, so please kindly
let me know if it's unfit or in any way out of line.