The Collaborative International Dictionary of English v.0.48:

Imido \Im"i*do\, a. (Chem.)
   Pertaining to, containing, or combined with, the radical NH,
   which is called the imido group.
   [1913 Webster]

   Imido acid, an organic acid, consisting of one or more acid
      radicals so united with the imido group that it contains
      replaceable acid hydrogen, and plays the part of an acid;
      as, uric acid, succinimide, etc., are imido acids.
      [1913 Webster]