Definition of AVAILABILITY. 1. : the quality or state of being available. 2. : an available person or thing.
Definition of EXECUTIVE OFFICER. : the officer second in command of a military or naval organization or vessel. ADVERTISEMENT. the officer second in command of a military or naval organization or vessel. ADVERTISEMENT.
executive agency-an agency of the executive branch of government. AEC, Atomic Energy Commission-a former executive agency (from 1946 to 1974) that was responsible for research into atomic energy and its peacetime uses in the United States.