functioning cuff buttons; working buttonholes on jacket sleeves
Refers to jacket cuffs where the buttons can actually be buttoned and unbuttoned, as opposed to decorative non-functioning buttons. Common in higher-end tailoring.
See also: 本開き
This jacket has functioning cuff buttons, so you can unbutton the sleeve buttons.
surgeon's cuffs; functional cuffs on a jacket
Same as sense 1, but specifically referred to as 'surgeon's cuffs' in English tailoring terminology. The term originates from the need for surgeons to roll up their sleeves without removing the jacket.
Surgeon's cuffs on suits are said to have been devised so that surgeons could easily roll up their sleeves.
Compound of 本 (ほん, 'real, genuine') and 切羽 (せっぱ, 'cuff slit/opening'). The term distinguishes functional buttonholes from decorative ones.