Pronunciation: (di-sō"sē-ā'shun, -shē-ā'-),[key] —n. 1. an act or instance of dissociating.
2. the state of being dissociated; disjunction; separation: the dissociation of church and state. 3. Physical Chem. a. the reversible resolution or decomposition of a complex substance into simpler constituents caused by variation in physical conditions, as when water gradually decomposes into hydrogen and oxygen under great heat in such a way that when the temperature is lowered the liberated elements recombine.
b. See electrolytic dissociation. 4. Psychiatry.the splitting off of a group of mental processes from the main body of consciousness, as in amnesia or certain forms of hysteria.