1560s, "hole or loop in which a button is caught," from button (n.) + hole (n.). The verb, also buttonhole, meaning "to detain (someone) in conversation against his will" (1862) was earlier button-hold (1834), from button-holder (1806, in this sense). The image is of holding someone by the coat-button so as to detain him.
From nine 'till eleven o'clock, a.m., hobnobbing and canoodling had been the order of the day. A man couldn't greet a friend from another county without unconsciously inserting his thumb into his coat button-hole from force of habit. [Tarboro (N.C.) Southerner, May 30, 1878, in an account of the Nash County Democratic convention]
updated on November 04, 2022