rider
‘one that rides, especially one who rides horses’
Lexical development traced from the Tamil root:
E. ridere, ridar, ryder < O.E. ridere ‘one who rides, trooper, knight, mounted warrior’ < ride < M.E. riden < O.E. ridan ‘sit or be carried on, move forward; rock; float, sail’ < Proto-G. ridan + er < raid < reidh-< Tamil uruḷ