fixation

definition: (histology) the preservation and hardening of a tissue sample to retain as nearly as possible the same relations they had in the living body
example:
speech part: noun
synonyms: fixing
definition: the activity of fastening something firmly in position
example:
speech part: noun
synonyms:
definition: an unhealthy and compulsive preoccupation with something or someone
example:
speech part: noun
synonyms: obsession
definition: an abnormal state in which development has stopped prematurely
example:
speech part: noun
synonyms: regression

How fixation is being used?