su·per·nu·mer·ar·y
adjective/ˌsuːpəˈnjuːmərəri/
/ˌsuːpərˈnuːməreri/
(formal)- more than you normally need; extra
多余的；过剩的；额外的 Word Originearly 17th cent.: from late Latin supernumerarius ‘(soldier) added to a legion after it is complete’, from Latin super numerum ‘beyond the number’.