protein(n = noun.substance) - any of a large group of nitrogenous organic compounds that are essential constituents of living cells; consist of polymers of amino acids; essential in the diet of animals for growth and for repair of tissues; can be obtained from meat and eggs and milk and legumes; "a diet high in protein"
is a kind of macromolecule, supermolecule
has particulars: capsid, gluten, recombinant protein, actomyosin, aleurone, amyloid, apoenzyme, compound protein, conjugated protein, enzyme, fibrin, filaggrin, growth factor, haptoglobin, iodinated protein, iodoprotein, nucleoprotein, opsin, phosphoprotein, plasma protein, prostate specific antigen, psa, proteome, simple protein, cytokine, ferritin, antibody
Derived form adjective proteinaceous₁

   In chemical analysis, the total nitrogenous material in vegetable or animal substances, obtained by multiplying the total nitrogen found by a factor, usually 6.25, assuming most proteids to contain approximately 16 per cent of nitrogen. [Webster 1913 Suppl.]

   any polymer of an amino acid joined by peptide (amide) bonds. Most natural proteins have alpha-amino acids as the monomeric constituents. All classical enzymes are composed of protein, and control most of the biochemical transformations carrie dout in living cells. They may be soluble, as casein, albumins, and other globular proteins, or insoluble (e. g. "structural proteins"), as collagen or keratin. "albumin", an older term for protein, is now used primarily to refer to certain specific soluble globular proteins found in eggs or blood serum, e.g. bovine serum albumin, the main soluble protein in teh serum of cattle, used as an enzymatically inert protein in biochemical research.
"In the 1913 dictionary, protein was defined as: “A body now known as alkali albumin, but originally considered to be the basis of all albuminous substances, whence its name.”" [1913 Webster]

protein, n. any of a group of organic compounds composed of one or more chains of amino acids and forming an essential part of all living organisms.

Derivative:
proteinaceous adj. proteinic adj. proteinous adj.

Etymology:
F prot{eacute}ine, G Protein f. Gk proteios primary

N  semiliquidity, stickiness, viscidity, viscosity, gummosity, glutinosity, mucosity, spissitude, crassitude, lentor, adhesiveness, inspissation, incrassation, thickening, jelly, mucilage, gelatin, gluten, carlock, fish glue, ichthyocol, ichthycolla, isinglass, mucus, phlegm, goo, pituite, lava, glair, starch, gluten, albumen, milk, cream, protein, treacle, gum, size, glue (tenacity), wax, beeswax, emulsion, soup, squash, mud, slush, slime, ooze, moisture, marsh, semifluid, semiliquid, tremellose, half melted, half frozen, milky, muddy, lacteal, lactean, lacteous, lactescent, lactiferous, emulsive, curdled, thick, succulent, uliginous, gelatinous, albuminous, mucilaginous, glutinous, glutenous, gelatin, mastic, amylaceous, ropy, clammy, clotted, viscid, viscous, sticky, tacky, gooey, slab, slabby, lentous, pituitous, mucid, muculent, mucous, gummy.

N  organization, organized world, organized nature, living nature, animated nature, living beings, organic remains, fossils, protoplasm, cytoplasm, protein, albumen, structure, organization, organism, biology, natural history, organic chemistry, anatomy, physiology, zoology, botany, microbiology, virology, bacteriology, mycology, naturalist, archegenesis, antherozoid, bioplasm, biotaxy, chromosome, dysmeromorph, ecology, oecology, erythroblast, gametangium, gamete, germinal matter, invagination, isogamy, oogamy, karyaster, macrogamete, microgamete, metabolism, anabolism, catabolism, metaplasm, ontogeny, ovary, ovum, oxidation, phylogeny, polymorphism, protozoa, spermary, spermatozoon, trophoplasm, vacuole, vertebration, zoogloea, zygote, Darwinism, neo-Darwinism, Lamarkism, neoLamarkism, Weismannism, morphology, taxonomy, organic, organized, karyoplasmic, unsegmentic, vacuolar, zoogloeic, zoogloeoid.

amyloid protein plaque, c-reactive protein, compound protein, conjugated protein, iodinated protein, mild silver protein, plasma protein, protein folding, protein molecule, silver protein, simple protein