Where does “Σημ” come from?

Σημ (Ancient Greek) comes from Hebrew שֵׁם, from Hebrew שמואל, from Hebrew שְׁמוּאֵל.

Ancestry of “Σημ”, step by step

Step	Language	Word	Meaning
1	Hebrew	שֵׁם	Shem; name; name of
2	Hebrew	שמואל	—
3	Hebrew	שְׁמוּאֵל	—