Cheek block

cheek block - A block with one end permanently attached to a surface.
chine - The location where the deck joins the lhull of the boat.
chockablock - When a line is pulled as tight as is can go, as when two blocks are pulled together.

cheek blocks - A sheave fitted on a spar inside a sort of cleat, as the cheek block for topsail sheet on the end of a gaff.
cheeks of the mast - The mast projections known as the hounds.

Cheek Block:
A block with one end permanently attached to a surface.
Cheeks:
(1) The two sides of a block.
(2) Pieces of timber attached to the mast below the masthead to support the trestle trees.

A cheek block is always open on one side. A turning block redirects a line. A foot block is a turning block lying on its side on the deck.

It will be seen that a is the peak end of the gaff; b is a cheek block for the topsail sheet; c is a block for the peak down haul, used also as signal halyards, hooked to an eyebolt screwed into the end of the gaff, ...

See also: Block, Keel, Forward, Boat, Mast