From Middle High German seiche f, seich m (“urine; urination”), from Old High German seih m (“urine”), from Old High German seihhen, seichen (“to melt, liquify, strain, urinate”), from Proto-West Germanic *saikijan, from Proto-Germanic *saikijaną (“to make drip”), causative of *sīhwaną (“to filter, strain”). Related to German seihen.