Meaning of RIDER in English
/ ˈraɪdə(r); NAmE / noun
a person who rides a horse, bicycle or motorcycle :
Three riders (= people riding horses) were approaching.
horses and their riders
She's an experienced rider.
a motorcycle dispatch rider
—picture at showjumping
rider (to sth) an extra piece of information that is added to an official document
late Old English rīdere mounted warrior, knight (see ride , -er ).
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005