The Collaborative International Dictionary of English v.0.48:

Bedrid \Bed"rid`\, Bedridden \Bed"rid`den\, a. [OE. bedrede, AS.
   bedreda, bedrida; from bed, bedd, a bed or couch + ridda a
   rider; cf. OHG. pettiriso, G. bettrise. See Bed, n., and
   Ride, v. i. ]
   Confined to the bed by sickness or infirmity. "Her decrepit,
   sick, and bedrid father." --Shak. "The estate of a bedridden
   old gentleman." --Macaulay.
   [1913 Webster] Bedright

WordNet (r) 3.0 (2006):

bedridden
    adj 1: confined to bed (by illness) [syn: bedfast,
           bedridden, bedrid, sick-abed]