earplug (for protection against noise or water)
cork stopper; (bottle) cork
nasal plug; wedge (in tusk mortise-and-tenon joint); wooden pin driven through tenon to hold it in place
wooden plug; cork; tampion
stop cock; stop valve; curb cock; shut-off valve
rubber stopper; rubber plug
inner plug (bottle, etc.)
tonsillolith; tonsil stone
castor aralia (Kalopanax septemlobus); prickly castor oil tree