noun.a compact usually solid piece of substantial material especially when worked or altered to serve a particular purpose: such as

• a block of ice
• blocks of cheese

noun.the piece of wood on which the neck of a person condemned to be beheaded is laid for execution

• put her neck on the block
• a wooden hat block

noun.a mold or form on which articles are shaped or displayed

• a wall of concrete blocks
• children playing with blocks

verb.to make (something) unsuitable for passage or progress by obstruction: obstruct

• A rock slide blocked the road.
• The entrance was blocked by a gate.

verb.to stop or hinder (someone or something) from moving through or going by

• A piece of food was blocking her airway.
• Main Street has been blocked off for the parade.

verb.to prevent (something, such as a process or action) from occurring

• My nose is all blocked up.
• Call a plumber. The sink is blocked up.