Web www.phrases.org.uk

As black as a Newgate's knocker

Meaning

Pitch black.

Origin

Refers to the heavy iron knocker on the gate of Newgate Prison, London. Several other similes are used to indicate blackness:

As black as a crow
As black as a raven's wing
As black as ink
As black as Hell
As black as Hades
As black as death
As black as the grave
As black as your hat
As black as thunder
As black as midnight
As black as pitch
As black as soot
As black as tar

... pretty much anything in fact, so long as it conjures up thoughts of darkness.

See other 'as xxx as yyy' phrases.