漏洞

漏洞	lòu dòng	leak / hole / gap / loophole
漏	lòu	to leak / to divulge / to leave out by mistake / waterclock or hourglass (old)
洞	dòng	cave / hole / zero (unambiguous spoken form when spelling out numbers) / CL:个
洞	tóng	used in 洪洞, a county in Shanxi