Gas price refers to the quantity of Eth you are willing to spend for every gas unit and it's measured in "Gwei". Wei is the smallest Ether unit and a Gwei is 1 billion Wei.
On the Eidoo Wallet you can set the Gas price in the "Advanced Settings" on the top left part of the "Transfer page", furthermore you can choose between: Low, Normal, High or customize it as you wish.
You can read more on how to send your currencies here:
How do I send my currencies on the Eidoo Wallet?