rider
/ˈraɪdə(r)/noun
1
- a person who is riding or who can ride a horse, bicycle, motorcycle, or snowboard乘客; 骑马（或自行车、摩托车）者; 踏滑雪板者。
2
- a condition or proviso added to something already said or decreed附加条款：
one rider to the deal-if the hurricane heads north, we run for shelter.
给决定加一个条件——如果飓风向北刮, 我们就避一避。
2.1
- a supplementary clause in a performer's contract specifying food, drink, etc., to be provided（演出合同中规定须提供食品、饮料等的）附加条款。
2.2
- Brit. an addition or amendment to a bill at its third reading〈英〉三读附加意见; 三读议案。
2.3
- Brit. a recommendation or comment added by the jury to a judicial verdict〈英〉（陪审团对裁定的）附加意见。
3
- a small weight positioned on the beam of a balance for fine adjustment（天平的）游码。
派生词
riderless
adjective词源
late Old English rīdere 'mounted warrior, knight' （see ride, -ER1）.