nasal plug; nose plug
A plug or stopper for the nose, used for swimming, medical purposes, or to block smells.
Some people use a nose plug when swimming.
wedge; wooden pin (in tusk tenon joint)
Architectural term: a wedge or wooden pin driven through a tenon in a tusk mortise-and-tenon joint to secure it.
In this traditional joinery, the tenon is secured with a wedge (鼻栓).
Compound of 鼻 (nose) and 栓 (plug, stopper). The architectural sense is a metaphorical extension based on the shape and function of a plug.