Final answer:
The term for deliberately trying to forget or not think about a painful or unwanted thought in psychology is suppression.
Step-by-step explanation:
The term for deliberately trying to forget or not think about a painful or unwanted thought in psychology is suppression. Suppression involves consciously pushing the thought or memory out of awareness. For example, if someone experiences a traumatic event and actively tries to avoid thinking about it, they are engaging in suppression. This defense mechanism can provide temporary relief but does not resolve the underlying issue.