'abecedarium' originates from Latin, specifically the word 'abecedarium,' where 'abeced-' referred to the first four letters of the alphabet.

'abecedarium' was used in medieval Latin to refer to a book for teaching the alphabet and eventually became the modern English word 'abecedarium.'

Initially, it meant 'a book for teaching the alphabet,' and this meaning has largely remained the same in modern usage.