The mouth.

–From the 1811 Dictionary of the Vulgar Tongue.

1811 Vulgar Tongue

An ancient game like hazard, played with dice: probably so named from the silence observed in playing at it.

Free Dictionary

A game of hazard played with cards in silence.
or
A silent, stupid person.

1811 Vulgar Tongue

A fellow who goes about by the water side picking up coals, nails, or other articles in the mud. Also a duck.

Wikipedia

A Mudlark is someone who scavenges in river mud for items of value, especially in London during the Industrial Revolution. Poor peasants would scavenge in the River Thames during low tide, searching for anything of value.

A fool, or thick-skulled fellow.

–From the 1811 Dictionary of the Vulgar Tongue.