Things that keep me awake at night.

I'd always thought the noun form of 'admonish' is 'admonition.' But lately, and I've been seeing it everywhere, like haunting, I see the word 'admonishment.' They both appear to be noun forms of the verb, but which is more correct? Admonishment sounds a lot like astonishment to me, and frankly almost a little made up, though clearly it is legit.

I think I will stick with 'admonition,' but I'm willing to be persuaded by anyone from the other camp with a compelling argument.

P.S. I Googled this little conundrum and found nothing--NOTHING!--relevant to my query as to which is more common, more preferable, etc. How often is it that Google is no help at all? Not very.