The best way to assess the 'nouniness' of a word is to see how it is used in the wild.
In other words, you should look in usage corpuses, Google Books etc. and form your own judgment (possibly with the help of some supplementary statistical analysis).
As Fumblefingers correctly notes in his comment:
Verbification, nounification, etc., are standard features of English, but dictionaries only tend to list the most common usages.
He also notes in a comment here,here,
"...I think you should ditch the notion that a word itself can properly be classed as a "noun". What matters is whether it functions as a noun in any given context."
Or as Edwin Ashworth stated in a comment on the same question,
"POS [part-of-speech] determination hinges on how a word functions in that usage / the syntactic environment; formal considerations; considerations from other languages; and yes – even semantic considerations. Linguists haven't agreed on the correct balance of these factors, nor even on undisputed tests for how a word is functioning in a usage."
So you can't expect even comprehensive dictionaries like the OED to cover the full range of possible usages of a word.
I would add to the comments by Fumblefingers and Edwin Ashworth that the elements of any living language are a constantly-moving target, so a statement about usage that was largely accurate 80 years ago may not be so today, and one that is largely accurate today may not be so 80 years from now.
For all the reasons cited above, a dictionary can never be fully categorical regarding the usage of any given word or expression (except, perhaps, with respect to terms that have fallen entirely out of use in contemporary speech and writing, and for which the usages have therefore become frozen).