washboard
🇺🇸
/ˈwɑːʃbɔːrd/
🇬🇧
/ˈwɒʃbɔːd/
A washboard is an old-fashioned tool with ridges that was used to scrub clothes clean before washing machines were invented. It can also refer to a musical instrument that looks similar to the laundry tool.
After the washing machine broke down, she had to use a washboard to clean her clothes.