[but.ton.hole] n (1561) 1: a slit or loop through which a button is passed
2. chiefly Brit: boutonniere
[2]buttonhole vt (1828) 1: to furnish with buttonholes
2: to work with buttonhole stitch -- but.ton.hol.er n [3]buttonhole vt [alter. of buttonhold] (1862): to detain in conversation by or as if by holding on to the outer garments of