|1. That part, or branch, of a drainage piping system which is without a free circulation of air.
2. The extended portion of a pipe that is closed at the end opposite its connection to another pipe, pump, fixture, or other device.
3. A branch leading from a soil, waste, vent pipe, building drain, or building sewer, and terminating at a developed length of two feet or more by means of a plug, cap, or other closed fitting, except piping serving as cleanout extensions to accessible areas.