丫子
see 腳丫子|脚丫子[jiao3 ya1 zi5]
哑子
mute person; dumb person; (more commonly called 啞巴|哑巴[ya3 ba5])
牙子
serrated edge; (old) middleman; broker
鸭子
duck; male prostitute (slang)
鸭仔蛋
balut (boiled duck egg with a partly-developed embryo, which is eaten from the shell)
赶鸭子上架
lit. to drive a duck onto a perch (idiom); fig. to push sb to do sth way beyond their ability