Treta čast (f)
(with) definite article: Tretata častoriginal: трета(та) част
3rd piece of a larger composed drone, remotest from the stock
Upper tuning piece of the drone, with resonance cavity.
Прашанов, Тодор [Prašanov, Todor]: Начална школа за гайда [Elementary tutor for bagpipe]. [1964: Ръководство за свирене на гайда [Manual for bagpipe playing]]. София [Sofija], 1974 [2], p.8.