The definition of every is each, all, or each group or interval.
(adjective)See every in Webster's New World College Dictionary
adjective
Origin: ME everiche < OE æfre ælc, lit., ever each
See every in American Heritage Dictionary 4
adjective
Origin:
Origin: Middle English everi, everich
Origin: , from Old English ǣfre ǣlc
Origin: : ǣfre, ever; see aiw- in Indo-European roots
Origin: + ǣlc, each; see līk- in Indo-European roots
. Usage Note: Every is representative of a large class of English words and expressions that are singular in form but felt to be plural in sense. The class includes, for example, noun phrases introduced by every, any, and certain uses of some. These expressions invariably take a singular verb; we say Every car has (not have) been tested. Anyone is (not are) liable to fall ill. But when a sentence contains a pronoun that refers to a previous noun phrase introduced by every, grammar and sense pull in different directions. The grammar of these expressions requires a singular pronoun, as in Every car must have its brakes tested, but the meaning often leads people to use the plural pronoun, as in Every car must have their brakes tested. The use of plural pronouns in such cases is common in speech, but it is still widely regarded as incorrect in writing. • The effort to adhere to the grammatical rule causes complications, however. The first is grammatical. When a pronoun refers to a phrase containing every or any that falls within a different independent clause, the pronoun cannot be singular. Thus it is not idiomatic to say Every man left; he took his raincoat with him. Nor can one say No one could be seen, could he? Writers unwilling to use plural forms in these examples must find another way of expressing their meaning, either by rephrasing the sentence so as to get the pronoun into the same clause (as in Every man left, taking his raincoat with him) or by substituting another word for every or any (as in All the men left; they took their raincoats with them). • The second complication is political. When a phrase introduced by every or any refers to a group containing both men and women, what should the gender of the singular pronoun be? This matter is discussed in the Usage Notes at he and they. See Usage Notes at all, any, each, either, he1, neither, none, they.Learn more about every