Protein

/ˈpɹəʊ.ti.ɪn/ noun

noun ·Moderate ·College level

Meaning at a glance

  • Primary sense: Any of numerous large, complex naturally-produced molecules composed of one or more long chains of amino acids, in which the amino acid groups are held together by peptide bonds.
  • Grammar: protein is listed as noun.
  • Nearest alternatives: albumin, albuminoid, amino acid, androcyte.
  • Useful contrasts: carbohydrate, glucose, inorganic molecule.
  • Usage evidence: A liter of milk contains about thirty grams of protein.

How to use "protein"

  1. Start with the primary definition, then check the part of speech before placing the word in a sentence.
  2. Compare nearby synonyms to make sure "protein" carries the exact meaning, tone, and strength you need.
  3. Use the example sentence as a context check. If your sentence uses the word differently, confirm that the grammar still fits.

Meaning check

  • Does the word fit the sentence's grammar?
  • Does it match the intended tone rather than only the dictionary definition?
  • Would a simpler synonym be clearer for the reader?
  • Is there enough surrounding context to prevent ambiguity?

Source and review context

This entry combines structured lexical data with WordToolSet review checks. Definitions, examples, synonyms, and usage notes may come from different source tables, so the page is designed to show evidence from more than one angle before you rely on "protein" in a final draft.

If a word has several senses, prefer the sense that matches your sentence's grammar and surrounding context. A correct definition can still be the wrong choice when the sentence needs a different register, emphasis, or level of specificity.

Before you rely on this definition

Read the first definition as a starting point, then check the example, synonyms, and part of speech before treating "protein" as the right word for your sentence.

If your draft is formal, technical, persuasive, or sensitive, compare "protein" with a nearby alternative so the final choice matches both meaning and reader expectation.

Compare nearby meanings

  • Use synonyms when you need a softer, stronger, simpler, or more specific word.
  • Use antonyms to check the boundary of the meaning and avoid accidental contrast.
  • Use the example sentence to confirm the word behaves naturally in context.
  • Keep the original wording when a replacement adds complexity without improving precision.

Definition decision workflow

1. Identify the role

Check whether "protein" is acting as noun in your sentence. A definition is only useful when the grammar matches the way the word is being used.

2. Test the nearest option

Compare it with "albumin" and other nearby choices to see whether the sentence needs a softer, stronger, or more familiar word.

3. Confirm with context

Use the example sentence below as an evidence check, then read your own sentence out loud to catch tone or rhythm problems.

Review note: Definition pages are checked for source coverage, sentence evidence, synonym support, and editorial insight before they are treated as approval-ready pages. If the evidence is too thin, the page remains available to users but is kept out of the approval-facing indexed inventory.

Final meaning check

Before publishing a sentence with "protein", ask whether the word helps the reader understand the idea faster. A precise word should reduce confusion, not simply make the sentence look more polished.

When the definition, synonym evidence, and example context point in the same direction, the word is usually a safer choice. When they conflict, revise the sentence or choose a clearer alternative.

Definitions

Noun
  1. 1
    Any of numerous large, complex naturally-produced molecules composed of one or more long chains of amino acids, in which the amino acid groups are held together by peptide bonds. countable

    "Proteins carry out the bulk of cellular functions, including relaying signals, providing structural support, and accelerating biochemical reactions."

  2. 2
    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 wordnet
  3. 3
    One of three major classes of food or source of food energy (4 kcal/gram) abundant in animal-derived foods (meat) and some vegetables, such as legumes. uncountable

    "Along with carbohydrates and fat, protein is one of the three main macronutrients that make up our diet. Furthermore, it is the only macronutrient that supplies us with amino acids, making it essential for survival."

  4. 4
    A food rich in protein, often a meat or meat substitute. countable

    "The preparation style should be the same for both proteins so that the side dishes compliment the meal."

Antonyms

carbohydrateglucoseinorganic moleculelipid

Example

"A liter of milk contains about thirty grams of protein."

Common questions

What does "protein" mean?

Any of numerous large, complex naturally-produced molecules composed of one or more long chains of amino acids, in which the amino acid groups are held together by peptide bonds.

What is a synonym for "protein"?

Common synonyms include: albumin, albuminoid, amino acid, androcyte, antheridium, antherozoid.

How do you use "protein" in a sentence?

A liter of milk contains about thirty grams of protein.

How do you pronounce "protein"?

Pronounced /ˈpɹəʊ.ti.ɪn/.

Etymology

From proto- + -ein. Suggested by Jöns Jacob Berzelius in a letter to Gerardus Johannes Mulder, from French protéine and German Protein, both coined based on Ancient Greek πρωτεῖος (prōteîos, “primary”), from πρῶτος (prôtos, “first”).

More for "protein"