The following terms define Building and Machine Parts
newel: large post at toot of stairs.
nag: wooden peg, pin, or block, especially one inserted into brickwork or between principal timbers of wall.
nonbearing wall: wall that supports no weight other than its own.
nosing: rounded edge of stair tread extending beyond riser.
notch: concave or V-shaped cut or indentation in edge or across surface.
nozzle: tube or vent used to expel fluid with force.