dissociation

UK: /dɪˌsəʊʃiˈeɪʃ^ən/, /dɪˌsəʊsiˈeɪʃ^ən/

US: /dɪˌsoʊʃiˈeɪʃən, -si-/

US: (di sō′sē ā′shən, -shē ā′-)

WordReference Random House Unabridged Dictionary of American English © 2026

dis•so•ci•a•tion  (di sō′sē ā′shən, -shē ā′-), n. 

1. an act or instance of dissociating.
2. the state of being dissociated;
   disjunction;
   separation:
   the dissociation of church and state.
3. Chemistry [Physical Chem.]
   • 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.
   • 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.

• dis-¹ + (as)sociation, modeled on Latin dissociātiō separation 1605–15

Collins Concise English Dictionary © HarperCollins Publishers::

dissociation / dɪˌsəʊsɪˈeɪʃən -ʃɪ-/ noun

1. the act of dissociating or the state of being dissociated
2. a reversible chemical change of the molecules of a single compound into two or more other molecules, atoms, ions, or radicals
3. a feeling of disconnection from the external world, occurring in episodes of short or long duration, often as the result of trauma
   Compare depersonalization2

WordReference Random House Learner's Dictionary of American English © 2026

dis•so•ci•ate /dɪˈsoʊʃiˌeɪt, -si-/   v. [~ + object + from + object] , -at•ed, -at•ing. 

1. to cut off or separate the association of; disconnect:
   He tried to dissociate himself from his past.

dis•so•ci•a•tion /dɪˌsoʊʃiˈeɪʃən, -si-/  n. [uncountable]

WordReference Random House Unabridged Dictionary of American English © 2026

dis•so•ci•ate  (di sō′shē āt′, -sē-), v., -at•ed, -at•ing. 
v.t. 

1. to sever the association of (oneself );
   separate:
   He tried to dissociate himself from the bigotry in his past.
2. to subject to dissociation.

v.i. 

3. to withdraw from association.
4. to undergo dissociation.

• dis-¹ + (as)sociate, modeled on Latin dissociātus, past participle of dissociāre to divide, sever 1605–15

dis•so′ci•a′tive, adj.