General English

  • adjective having exactly the same amount as something else
  • noun a person who is on the same level as someone else
  • verb to give a particular result

General Science

  • verb to be the same in value as a number


Information & Library Science

  • adjective same in size, amount or degree

Origin & History of “equal”

Latin aequus (a word of unknown ancestry) meant ‘level’ or ‘even’. From it was derived the adjective aequālis ‘equal’, which has provided the term for ‘equal’ in all the modern romance languages, including French égal (source of English egalitarian (19th c.)), Italian uguale, and Spanish igual. English, however, is the only Germanic language in which it constitutes a major borrowing.

English also possesses, of course, a host of related words, including adequate (17th c.), equanimity (17th c.), equate (15th c.), equation (14th c.) equator (14th c.) (etymologically the line of latitude that ‘equalizes’ day and night), and iniquity (14th c.) (etymologically the equivalent of inequality), not to mention all those beginning with the prefix equi-, such as equidistant (16th c.), equilibrium (17th c.) (literally ‘equal balance’, from Latin lībra ‘balance’), equinox (14th c.), equity (14th c.), and equivalent (15th c.).