traumatic experience
Refers to a psychologically traumatic event, often used in medical or psychological contexts.
He has been carrying the traumatic experience from his childhood for a long time.
トラウマ is a more common, casual term for psychological trauma, while 外傷体験 is a formal, clinical term often used in medical or psychological contexts.
Compound of 外傷 (がいしょう, 'external wound; injury') and 体験 (たいけん, 'experience'), literally 'external wound experience', used to mean a psychologically traumatic experience.