a-to-z

The phrase "A to Z" is a metaphorical construction that leverages the fundamental ordering of the Latin alphabet, which English adopted. The letter 'A' (alpha in Greek) and 'Z' (zeta in Greek; zed/zee in English) have been symbolically used since at least the medieval period to denote the first and last items in a set, drawing from the Biblical reference "I am the Alpha and the Omega" (the first and last letters of the Greek alphabet) to signify completeness. By the early 20th century, this alphabetic symbolism was lexicalized into the hyphenated compound "A-to-Z" in English, transforming the literal sequence of letters into an adjective and adverb meaning "covering everything from start to finish." Its logic is purely symbolic, using the culturally understood boundaries of the alphabet as a metaphor for totality and comprehensiveness.

This is a fixed lexicalized phrase composed of the first and last letters of the English alphabet. 'A' and 'Z' are not morphemes in the traditional sense but are symbols representing the start and end points of a sequence.