Poklopac (m)
original: (поклопац)
non-return valve of the blowpipe
A general term, not encountered in other sources specialised in musicology.
Gojković, Andrijana: Narodni muzički instrumenti [Folk musical instruments]. Beograd, 1979, p.152 (➺ Poklopčić).
ws (linguistics [➺ Dictionaries, &c.])