It's technically pronounced z-ee-n (because it's short for magazine) but lots of people who aren't familiar with the origin and/or learned the word online say z

It's technically pronounced z-ee-n (because it's short for magazine) but lots of people who aren't familiar with the origin and/or learned the word online say z-eye-n and it doesn't do them any harm. Both pronunciations are usually understandable from context.