A Plumbing

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. (informal) A system of vessels or ducts in the human body, especially the genitourinary system.

4. (informal, figuratively) Practical, concrete work serving to support other work.
5. This is not scientific research as such: it's just plumbing.
6. (countable) A Murasugi sum where each disk summed along has its boundary subdivided into four segments.

(genitourinary system): waterworks (informal)