nipple

3.乳头状物品；（机器的）喷嘴a small metal, plastic or rubber object that is shaped like a nipple with a small hole in the end, especially one that is used as part of a machine to direct oil, etc. into a particular place

1.奶头,(奶瓶的)橡皮奶头

2.(皮肤,山顶,金属面,玻璃面等的)乳头状突起;(枪炮的)火门;【机】喷灯喷嘴,螺纹接套

1.a small round raised area of dark flesh on a woman’s breast or on a man’s chest

2.the plastic or rubber part on the end of a baby’s bottle that it sucks milk through

3.a small object that is shaped like a nipple, used as part of a machine or as a cover for something