Plumbing

noun

1. The pipes, together with the joints, tanks, stopcocks, taps and other fixtures of a water, gas or sewage system in a house or other building.
2. The trade or occupation of a plumber.
3. A system of vessels or ducts in the human body, especially the genitourinary system.

   "My plumbing was playing up, so I had to see the doctor."

4. Practical, concrete work serving to support other work.

   "This is not scientific research as such: it's just plumbing."

5. A Murasugi sum where each disk summed along has its boundary subdivided into four segments.