Seems fairly straightforward. If (and only if) you already have gold status on another airline or alliance (that is not an Etihad partner airline), Etihad will give you gold status to try them out.
As an Etihad Guest Gold member you enjoy benefits such as:
- 50% Extra Bonus Miles - Enjoy 50% additional Etihad guest miles in every flight you take on Etihad Airways
- Extra Baggage Allowance - Enjoy 15 kilos additional baggage allowance on all applicable flights*
- Enhanced Lounge Access - You and a guest are invited to enjoy our luxurious Business Class Lounges before you fly across our network
- Guaranteed seats - If you make a booking at least 24 hours in advance, we will guarantee you an Economy Class seat on an Etihad Airways flight of your choice - even if the flight is fully booked.
- Fast-Track Access - Upon arrival at your destination, skip the queue at border control to enjoy a speedy exit*
See link for how to apply and what you need to send them.