A tool used by carpenters and masons to mark straight lines; it consists of a container with an inked cord that is pulled tight and snapped against a surface to leave a mark.

used in the names of various aquatic or water-dwelling animals that are not biologically fish, such as 鲍鱼 bào​yú (abalone), 鳄鱼 è​yú (crocodile), or 章鱼 zhāng​yú (octopus)