A B C D E F-G H I-J-K L-M-N O P-Q R S T U-Z

Obsessions: Recurring irrational or disturbing thoughts a person cannot prevent. A driving, irresistible idea and when combined with emotion, is likely to result in action, sometimes endlessly repeated.

Obsessive-compulsive Disorder: Extreme preoccupation with certain thoughts and/or compulsive performance of certain behaviors, both of which occur in ritualistic or unavoidable fashion.

Operator: Synonymous with hypnotist or hypnotherapist.

Overt: An adjective applied to behavior that can be observed without the aid of special instruments.