No. You won’t be able to redeem Etihad Guest Miles for cash. The points can be redeemed for flights, gift cards, merchandise, hotel stays etc.
If you want to be able to redeem for flights and cash, consider getting a travel rewards credit card. For example, it can be the Discover it® Miles card. It allows to earn 1.5 miles per dollar on all purchases. The miles you earn your first year, will be matched at the end of the year (provided you are a new cardmember). Earned miles can be redeemed as travel statement credits or as cash deposited to your account. When redeeming for travel statement credits, you can cover the cost of any airline ticket with miles. The card has no annual fee and no foreign transaction fees.