>Deny and list have both been words for more than 1500 years.

Neat, but denylist isn't a word. Thank you for proving my point.

>Unless someone is trying to be particularly daft, it’s pretty straightforward to put them together and grok a mean.

Except it's not, especially for those who are not as privileged and learn English as a second language. "Broad" and "way" are two words that when put together mean something very different. QED.

>Much better than blacklist.

Not at all, since it's not a word.

>If you didn’t have a dictionary, you would never know.

Thank God the word predates computers and we all know what it means.