What does 'Black as Newgate's knocker' mean?

If things are as black as Newgate's knocker, they are very bad. Newgate was an infamous prison in England, so its door knocker meant trouble.

Idioms similar to 'Black as Newgate's knocker'

All idioms have been editorially reviewed, and submitted idioms may have been edited for correctness and completeness.

See also: