[kāi kǒu]
(开口说话) open one's mouth; start to talk; begin to speak
hold one's tongue
不开口
find it difficult to bring the matter up
难以开口
(开刃) put the first edge on a knife; sharpen the edge of a new blade
opening aperture; [纺] shedding; aperture; placketing; orifice; fent; hiascent