The word alphabet comes from the first two letters of the Greek alphabet: alpha and beta. It was first used, in its Latin form, alphabetum, by Tertullian during the 2nd–3rd century CE and by St. Jerome.
These little epiphanies are always fun. Like when you realise how many maths and astronomy terms are just romanised Arabic words like Algebra and Algorithm.
Another fun one that I wasn't smart enough to notice on my own is that the Hindu-Arabic numerals have the same number of angles in the symbols as the number they represent.
Pretty much. English borrowed it from Latin because it's posh. And Latin borrowed it from Greek because it's posh. But at the end of the day it's in the same spirit as "the ABC", or Latin "abecedarius".
It is kind of the same suffix but the story is a mess.
That -ario and all words using it are reborrowed* from Latin. And originally it was two related suffixes, fulfilling two purposes:
masculine -arius, feminine -aria: transform noun into adjective. Like "a be ce de" (ABCD) into "abecedarius" (alphabetic).
neuter -arium: noun denoting a place for another noun. Like "dictio" (saying) into "dictionarium" (dictionary, or "where you store sayings")
Except that Latin allowed you to use an adjective as if it was a noun (Spanish still does it), so that "abecedarius" ended as a substantive again. And Spanish merged Latin masculine and neuter, further conflating both versions of the suffix.
*the inherited doublet is the -ero in llavero (place for keys) and herrero (related to iron - professions took the suffix and systematised the re-substantivisation).
Fun fact - in Polish language the word alfabet exists as a technical name of the alphabet. There is also a more casual word, often used by children: abecadło which is basically polish way of saying "The ABCs".
There's a series on Prime via The Great Courses Collection about the origins of language. (Almost?) all languages derive their names like this, but that's like, a throw away line in a much deeper series.
Many Indian languages use some version of 'akshara', which means 'unchanging' or 'indestructible'. (I guess the alphabet does change, but too slowly for us to notice.) Most Indian languages start the alphabet with all the vowels, so 'first n letters' would be unpronouncable.
Yeah. Little known fact, they named their company after their original product, but struggled with how to turn in profit, so they created a Google subsidiary which invented a search engine. True story.