[def-uh-nish-uh n]
  1. the act of defining, or of making something definite, distinct, or clear: We need a better definition of her responsibilities.
  2. the formal statement of the meaning or significance of a word, phrase, idiom, etc., as found in dictionaries. An online dictionary resource, such as, can give users direct, immediate access to the definitions of a term, allowing them to compare definitions from various dictionaries and stay up to date with an ever-expanding vocabulary.
  3. the condition of being definite, distinct, or clearly outlined: His biceps have great muscle definition.
  4. Optics. sharpness of the image formed by an optical system.
  5. Radio and Television. the accuracy of sound or picture reproduction.

Origin of definition

1350–1400; Middle English diffinicioun < Old French diffinition < Latin dēfīnītiōn- (stem of dēfīnītiō), equivalent to dēfīnīt(us) (see definite) + -iōn- -ion
Related formsdef·i·ni·tion·al, adjectivedef·i·ni·tion·al·ly, adverbpre·def·i·ni·tion, nounre·def·i·ni·tion, nounself-def·i·ni·tion, nounsub·def·i·ni·tion, noun Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for definitions

Contemporary Examples of definitions

Historical Examples of definitions

  • Let us avoid for the moment the treacherous territory of definitions.

  • Here is a choice of three definitions, but not one of them is by itself satisfying.


    Benjamin Taylor

  • We are growing more cautious, perhaps, with our definitions.


    James Anthony Froude

  • Now it is not only in our definitions that we need to be precise and to think clearly.

  • Oh, how tedious it was, pronouncing word after word, and giving their definitions!

    Pretty Madcap Dorothy

    Laura Jean Libbey

British Dictionary definitions for definitions


  1. a formal and concise statement of the meaning of a word, phrase, etc
  2. the act of defining a word, phrase, etc
  3. specification of the essential properties of something, or of the criteria which uniquely identify it
  4. the act of making clear or definite
  5. the state or condition of being clearly defined or definite
  6. a measure of the clarity of an optical, photographic, or television image as characterized by its sharpness and contrast
Derived Formsdefinitional, adjective
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for definitions



late 14c., "decision, setting of boundaries," from Old French definicion, from Latin definitionem (nominative definitio), noun of action from past participle stem of definire (see define).

In logic, meaning "act of stating what something means" is from 1640s; meaning "a statement of the essential nature of something" is from late 14c.; the special focus on words developed after c.1550. Meaning "degree of distinctness of the details in a picture" is from 1889.

Online Etymology Dictionary, © 2010 Douglas Harper