definition

1. a statement of what a word or expression means

2. the clear edges or shape that something has that make it easy to see

View the full definition in the Macmillan Dictionary.

Origin and usage

The noun definition comes from Latin via Old French and was first recorded in English in the late 14th century. It was first used to mean the explanation of a word or phrase in the mid 16th century.

Examples

Today is Dictionary Day in the US, an annual celebration of the work of Noah Webster, the undisputed father of American lexicography. Webster was born on October 16 1758 in Connecticut and graduated from Yale College in 1778. After training as a lawyer Webster turned to education and the writing of educational books, including spelling books. Webster published his first dictionary in 1806 and his ‘American Dictionary of the English Language’ in 1828. Webster was a champion of spelling reform and his works helped to popularize what he regarded as the rational spellings that continue to distinguish American from British English today. Definitions are at the heart of a monolingual dictionary, and many of Webster’s definitions read as well today as when they were first published over 200 years ago.

Quotations

“As nothing can be proved but by supposing something intuitively known, and evident without proof, so nothing can be defined but by the use of words too plain to admit a definition.”
(Samuel Johnson, Preface to Dictionary of the English Language, 1755)

“Definition: In lexicography, an explanation of the signification of a word or term, or of what a word is understood to express.”
(Noah Webster, American Dictionary of the English Language, 1828)