I became familiar with the term postulant viewing The Nun’s Story on Turner Classic Movies channel. The daughter of a surgeon in Belgium was trained in a convent to become a nun in the Congo.
A postulant is person taking the first step in religious life before entering the novitiate and receiving the habit(the habit being a nun in this case) They have to renounce all associations with the trappings and evils of the world, avoid all speaking without necessity(grand silence).
Obedience, Chastity, and poverty were three year commitments in the cloister. Too much penance is as bad as too little according reverend mothers. Displays of pride are also punished.
Audry Hepburn’s character learned that many pregnant Congo women did not trust their child’s delivery to doctors preferring the filth of a pit in the jungle. She had to suppress verbal references to her father who was a well known, but not a Christian surgeon.