supplementary/ˌsʌplɪˈmentrɪ; ?@ -terɪ; ˌsʌplə`mɛntərɪ/~ (to sth)1 additional; extra 增补的; 补充的; 附加的 a supplementary payment, lecture, item 额外的付款、 讲座、 项目.2 (mathematics 数) (of an angle) making a total of 180 with another angle （指角）补角的.
牛津英汉双解词典