buttonhole

Buttonhole is easy to pin down as a noun referring to the slit or loop through which a button is passed to fasten something, but its shift to a verb meaning "to detain in conversation" requires some explanation. Buttonhole is an alteration of another verb now long out of use: buttonhold, which literally meant to hold on to the buttons or lapels of someone's coat when speaking to him or her. In the mid-19th century, English speakers altered the verb to buttonhole, perhaps as a result of hearing buttonhold as buttonholed. The overlap is apparent in an early instance of this spelling in an 1862 London publication called All Year Round: "The man who is button-holed, or held … and must listen to half an hour's harangue about nothing interesting."