Source : Webster's Revised Unabridged Dictionary (1913)

Valetudinarian \Val`e*tu`di*na"ri*an\, a. [L. valetudinarius,
   from valetudo state of health, health, ill health, fr. valere
   to be strong or well: cf. F. val['e]tudinaire. See
   {Valiant}.]
   Of infirm health; seeking to recover health; sickly; weakly;
   infirm.

         My feeble health and valetudinarian stomach.
                                                  --Coleridge.

         The virtue which the world wants is a healthful virtue,
         not a valetudinarian virtue.             --Macaulay.

Valetudinarian \Val`e*tu`di*na"ri*an\, n.
   A person of a weak or sickly constitution; one who is seeking
   to recover health.

         Valetudinarians must live where they can command and
         scold.                                   --Swift.

Source : WordNet®

valetudinarian
     adj : of or relating to or characteristic of a person who is a
           valetudinarian
     n : weak or sickly person especially one morbidly concerned with
         his or her health