In Arabic, it’s spelled with the initial letter ghayn, which is written in the same form as ‘ayn, except that ghayn has a dot to tell it apart. The similarity of shape and name reflects that the two sounds have been associated since Proto-Semitic. Hebrew has one letter, ‘ayin, that corresponds to these two different letters in Arabic. Cognates that have ‘ayin in Hebrew might start with one or the other in other Semitic languages.
The appendix of Semitic roots in the 4th edition of the American Heritage Dictionary lists a couple Hebrew words starting with ‘ayin that came from a Proto-Semitic root using the ghayn sound: ‘Eden, ‘omer, Lag b‘Omer. The ones listed in the AHD4 are just Hebrew loanwords found in English; there’s got to be many more. If it weren’t so late at night and me about to bed down, I would look up more examples for you, but you get the idea. Gaza is one more example of this.