What is the origin of the word alphabet?

The word alphabet derives from the first two letters of the Greek alphabet: alpha and beta. 

The English word alphabet came into Middle English from the Late Latin word alphabetum. Thisin turn originated in the Greek ἀλφάβητος (alphabētos), from alpha and beta, the first two letters of the Greek alphabet.

These ultimately links back to the first two letters  of the Phoenician alphabet. These originally meant ox and house.  Source

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