Learn how to say Hypnosis correctly in English with this tutorial pronunciation video.
Oxford dictionary definition of the word hypnosis:
the induction of a state of consciousness in which a person apparently loses the power of voluntary action and is highly responsive to suggestion or direction. Its use in therapy, typically to recover suppressed memories or to allow modification of behaviour, has been revived but is still controversial.
a hypnotic state:
I was regressed under hypnosis
late 19th century: from Greek hupnos ‘sleep’ + -osis