Where does “zerum” come from?

zerum (New Latin) comes from Medieval Latin zephirum, from Arabic صِفْر, from Sanskrit शून्य, from Proto-Indo-European ḱówH-.

Ancestry of “zerum”, step by step

Step	Language	Word	Meaning
1	Medieval Latin	zephirum	zero
2	Arabic	صِفْر	zero, nothing, empty, void; nothing, cipher;...
3	Sanskrit	शून्य	zero; cipher, cypher; blank, deserted
4	Proto-Indo-European	ḱówH-	—