The Collaborative International Dictionary
Proteid \Pro"te*id\, n. [Gr. prw^tos first.] (Physiol. Chem.) an older, imprecise term replaced by {protein}.
Note: Defined in the 1913 Webster as ``One of a class of amorphous nitrogenous principles, containing, as a rule, a small amount of sulphur; an albuminoid, as blood fibrin, casein of milk, etc. Proteids are present in nearly all animal fluids and make up the greater part of animal tissues and organs. They are also important constituents of vegetable tissues. See 2d Note under Food.'' -- Pro"te*id, a.
Defensive proteid (Physiol. Chem.), one of a class of proteid substances, present in some animal tissues and fluids, that make the body immune to certain infectious diseases by destroying or rendering inactive the toxic products of bacterial growth; -- this is an older term replaced by more precise modern immunological concepts such as antibody and immunoglobulin. [archaic]