(used of count nouns) each and all of the members of a group considered singly and without exception
"every person is mortal"
"every party is welcome"
"had every hope of success"
"every chance of winning"
each and all of a series of entities or intervals as specified
"every third seat"
"every two hours"
All of a countable group (considered individually), without exception.
"Every student in the class received an award at the ceremony."
A surname.
"My neighbor, Mr. Every, has been living in our town for twenty years."
The word "every" comes directly from Middle English forms like everich and Old English compounds meaning "each and every." It entered modern usage as a single term that originally combined the concepts of "always" (ever) with "any one at all" to emphasize total inclusion.