[dis.so.ci.a.tion] n (1611) 1: the act or process of dissociating: the state of being dissociated: as a: the process by which a chemical combination breaks up into simpler constituents; esp: one that results from the action of energy (as heat) on a gas or of a solvent on a dissolved substance b: the separation of whole segments of the personality (as in multiple personality) or of discrete mental processes (as in the schizophrenias) from the mainstream of consciousness or of behavior
2: the property inherent in some biological stocks (as of certain bacteria) of differentiating into two or more distinct and relatively permanent strains; also: such a strain -- dis.so.cia.tive adj