Meaning of “hypnosis” - Learner’s Dictionary

hypnosis

noun [ U ] uk us /hɪpˈnəʊsɪs/

a mental state like sleep, in which a person's thoughts can be easily influenced by someone else:

Police placed witnesses under hypnosis in an effort to gain additional information.

(Definition of “hypnosis” from the Cambridge Learner’s Dictionary © Cambridge University Press)