Kitchen Sink
A unit used to wash food and dishes. Also, holds and releases water. Has a faucet attached to sink with all sorts of different items. For example: soap dispenser, sprayer, instant hot water source, cold water tap, and more.
Knockout Plug
PVC test plug
Laundry Tubs
A deeper sink to wash clothes or have a washing machine discharge hose empty into.
Lavatory (Lav)
A bowl with running water and drainage system. Also, commonly used as a another name for bathroom.
Leader
Pipe carrying rainwater to the ground or sewer.
Lock Nut
A fitting the joins two pieces of pipe together.
Male Fitting
Fittings are used in pipe and plumbing systems to connect straight pipe or tubing sections, to adapt to different sizes or shapes, and for other purposes, such as regulating or measuring fluid flow.
Male Threads
Threads on the outside of a pipe.
Manifold
A fitting that connects a number of branches to the main; serves as a distribution point.
Nipple
A short stub of pipe, usually threaded steel, brass, chlorinated polyvinyl chloride (CPVC) or copper; occasionally just bare copper. A nipple is defined as being a short stub of pipe which has external male pipe threads at each end, for connecting two other fittings. Nipples are commonly used for plumbing and hoses, and second as valves for funnels and pipes
No-Hub Connector
A device that hold two pieces of pipe together weather there the same or different. Example: PVC and ABS
O-Ring
Round rubber washer that makes a watertight seal.
Overflow Tube
A verticle tube inside the tank of the toilet that throws water into your bowl in-case the ballcock or Fillvalve breaks down.
via- Wikipedia