"of or pertaining to panic; inclined to panic," 1865, in a U.S. Civil War context, from panic (n.1) + -y (2). Related: Panickiness.
I remonstrated against it in private conversations and in written despatches, until I am very certain that the parties to whom my remonstrances were made, and those around them, began to think I was getting panicky, as they say, and I had to stop it. [Brig. Gen. A.L. Lee, testimony on the Red River Expedition before the Joint Committee on the Conduct of the War, 38th Congress, 2nd session, Washington, 1865]