Medical Definition of substitution
1: a chemical reaction in which one or more atoms or groups in a molecule are replaced by equivalent atoms or groups to form at least two products; especially : the replacement of hydrogen in an organic compound by another element or group
2a: the turning from an obstructed desire to another desire whose gratification is socially acceptableb: the turning from an obstructed form of behavior to a different and often more primitive expression of the same tendency <a substitution neurosis>c: the reacting to each of a set of stimuli by a response prescribed in a key <a substitution test for speed of learning new responses>
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Dictionary: Definition of "substitution" Spanish Central: Translation of "substitution" Nglish: Translation of "substitution" for Spanish speakers Britannica English: Translation of "substitution" for Arabic speakers Britannica.com: Encyclopedia article about "substitution"
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