1. receptive or responsive to personal interaction and other external stimuli. A client in psychotherapy, for example, is thought to be accessible if he or she responds to the therapist in a way that facilitates the development of rapport and, ultimately, fosters the examination of cognitive, emotional, and behavioral issues.
2. retrievable through memory or other cognitive processes, as in attitude accessibility for example.
3. of a building or other site and its facilities and fixtures: easy to approach, enter, or use, particularly by people with disabilities.
4. in a tissue, reachable by means of standard surgical or diagnostic procedures.
5. in a Markov chain, describing a state j that there is a possibility of reaching from another state i in some number of steps. —accessibility n.