globulin

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Any of a class of proteins that are found extensively in blood plasma, milk, muscle, and plant seeds and that are insoluble in pure water and half saturated ammonium sulfate, soluble in dilute salt solution, and coagulable by heat.

Century Dictionary and Cyclopedia

1. n. The general name of a class of native proteids allied to the albumins, but distinguished from them by being insoluble in pure water. The globulins are soluble in weak acids and alkalis and dilute salt-solutions, but most of them are precipitated when their solutions are saturated with salt. They include vitellin, myosin, paraglobulin, and other bodies.
2. n. A protein body occurring, mixed with albumin, in the cells of the crystalline lens of the eye (whence it is also called crystallin). It resembles albumin, but differs from it in being precipitated from both acid and alkaline solutions by exact neutralization, and in being completely thrown down from its solutions by carbonic-acid gas.
3. n. In botany, a name given by Turpin to starch-granules, and by Kieser to chlorophyl-granules, and now applied to such proteids as are soluble in a strong solution of salt, but not in pure water.

Wiktionary

1. n. biochemistry A protein found in blood and various other structures; one of the two parts of hæmoglobin.

GNU Webster's 1913

1. n. (Phisiol. Chem.) An albuminous body, insoluble in water, but soluble in dilute solutions of salt. It is present in the red blood corpuscles united with hæmatin to form hæmoglobin. It is also found in the crystalline lens of the eye, and in blood serum, and is sometimes called crystallin. In the plural the word is applied to a group of proteid substances such as vitellin, myosin, fibrinogen, etc., all insoluble in water, but soluble in dilute salt solutions.

WordNet 3.0

1. n. a family of proteins found in blood and milk and muscle and in plant seed