䨒yǔ

[书] Ⅰ  （流水的声音） the sound of flowing water Ⅱ  （下雨） (of rain) fall; rain Ⅲ  （羽毛） feather; plume

• once more
• once or twice
• once upon a time
• on duty
• one
• one after another
• one and the same
• one another
• on earth
• one by one
• one day
• on end
• one or two
• oneself
• one-sided
• one's native language
• onetime
• one-way ticket
• on exhibition
• on fire
• on foot
• ongoing
• on guard
• on hand
• onion