godan verb (-su), transitive verb
wear out; make old
Transitive verb meaning to use something until it becomes old or worn out. Often used for clothes, tools, or everyday items.
この靴を古すまで履き続けるつもりだ。
I plan to keep wearing these shoes until I wear them out.
彼はお気に入りのジーンズを古し
He wore out his favorite jeans.