Zaytun
Yes. The word 'zaytun' (olive) appears in Surah At-Tin (95:1): 'By the Fig and the Olive.'
Zaytun is used as a unisex name in some communities, though in practice it is more often given to girls in Malay contexts and can be unisex elsewhere.
Yes. Because it is a Quranic word and a positive natural symbol, it is widely considered appropriate as a Muslim personal name.
In Arabic and Urdu script it is written as زيتون (Zaytun/Zaitun).
Yes. Variants such as Zaitun and Zaitoon are commonly used in Malay and Indonesian naming traditions.