The name of the Old English runic alphabet Fuþorc (or transliterated into Furthark or Furthorc) is, just like the word alphabet formed by a portmanteau of its first few letters.
The Scandinavian variants [of Fuþorc] are also known as futhark or fuþark (derived from their first six letters of the alphabet: F, U, Þ, A, R, and K); the Anglo-Saxon variant is futhorc or fuþorc (due to sound changes undergone in Old English by the names of those six letters).
As you can see from the first six runes in Fuþorc, it is formed from their collective characters.
ᛓ ᚢ ᚦ ᚩ ᚱ ᚳ F U þ(th) O R C
Alphabet comes from a portmanteau of the two first letters: alpha (α) and beta (β), forming alphabet
Do other languages use this to name their scripts?
Why are they formed like this?
I moved this from EL&U due to it being judged off-topic