Where does “Algol” come from?

Algol (Italian) comes from Arabic غول, from Arabic و, from Persian یا, from Arabic يَا — {{m|en|O|id=vocative}}.

Ancestry of “Algol”, step by step

Step	Language	Word	Meaning
1	Arabic	غول	ape, orangutan; ghoul, desert demon; demon, jinn,...
2	Arabic	و	and, "comma", "semi-colon"; a divider of words or...
3	Persian	یا	API •; or; either
4	Arabic	يَا	{{m\|en\|O\|id=vocative}}

Algol — Etymology, Origin & Word History | Etymology Explorer