Plasma protein terminology: "globulins" v. "immunoglobulins"

As Dr. Flatland indicated, the value for globulin concentration on a serum or plasma chemistry panel is determined mathematically:

[Total protein] - [Albumin] = [Globulins]

So, in the context of clinical chemistry, "globulins" means any proteins detected by the biuret method, except albumin.

Sometimes people say "globulins" when they really mean "immunoglobulins", which means antibodies.  An immunoglobulin (Ig) is a type of globulin, but the terms are not synonymous because the globulin fraction also comprises many non-Ig proteins, including coagulation factors, acute phase proteins, transport proteins, enzymes, hormones, cytokines ... and I'm probably leaving some out.