Definition of protein in English:

Share this entry


Pronunciation: /ˈprəʊtiːn/


1Any of a class of nitrogenous organic compounds which have large molecules composed of one or more long chains of amino acids and are an essential part of all living organisms, especially as structural components of body tissues such as muscle, hair, etc., and as enzymes and antibodies: a protein found in wheat animal proteins
More example sentences
  • The 75-kD fusion protein was purified four times by affinity binding to an amylose resin.
  • Western blot analysis confirmed that this truncated fusion protein is expressed in yeast (data not shown).
  • The scientists have genetically engineered the animals to produce a green fluorescent protein in cells throughout the abdomen.
1.1 [mass noun] Proteins collectively, especially as a dietary component: a diet high in protein
More example sentences
  • Some postmenopausal women swear that dietary soy protein combats their hot flushes.
  • Rice is high in protein, but these proteins are low in the essential amino acid lysine.
  • There would be little rice and even less protein for the family before the rains came again in May.



Pronunciation: /prəʊtɪˈneɪʃəs/
Example sentences
  • Transport of polyelectrolytes, in particular of nucleic acid fragments, through proteinaceous pores in membranes has also been reported.
  • They include activated charcoal, Congo red, India ink, proteinaceous compounds and fluorescent materials.
  • Since mitochondria have two membranes, precursors targeted to the matrix must cross both barriers, presumably through proteinaceous channels.


Pronunciation: /prəʊˈtiːnɪk/
Example sentences
  • It is expected that a similar approach will succeed for other proteinic occupational antigens.
  • The proteinic nature of the adhesive material is confirmed by tests on the influence of various reagents on the adhesive strength.
  • The inner epithelium consists of cells enclosing large heterogeneous spherules composed of proteinic and glucidic fractions.


Pronunciation: /prəʊˈtiːnəs/ /prəʊˈtiːɪnəs/
Example sentences
  • The protons are delayed on the proteinous surface due to the high density of proton-binding sites that form a concentrated layer of an undilutable buffer.
  • Indicating apparently proteinous reddish strips with paler coloured borders I asked the waitress if it was some sort of ersatz bacon, to which she replied: ‘So you don't eat a lot of vegetables, sir?’
  • The lamellar (originally largely proteinous) sublayer of each ligament has been replaced by localized concentrations of framboidal pyrite.


Mid 19th century: from French protéine, German Protein, from Greek prōteios 'primary', from prōtos 'first'.

  • first from Old English:

    The Old English word first goes back to an ancient root which is shared by Latin primus (as in prime), and Greek prōtos (as in protein (mid 19th century) and prototype (mid 16th century)). The expression first come, first served goes back to the Middle Ages and is found in the poetry of Geoffrey Chaucer. It was originally used in the context of milling, when a mill would serve the whole community. The first person to bring their corn to the mill would be the first person to have it ground. The first among equals is the member of a group that has the highest status. It is a translation of the Latin phrase primus inter pares, which was used as a title by Roman emperors. Many will know it today as the title of a Jeffrey Archer novel published in 1984. In Scotland to first-foot (early 19th century) is to be the first person to cross the threshold of a house in the New Year. Traditionally, it is thought lucky for that person to be a dark-haired man.

For editors and proofreaders

Line breaks: pro|tein

Share this entry

What do you find interesting about this word or phrase?

Comments that don't adhere to our Community Guidelines may be moderated or removed.