Post-Traumatic Stress Disorder (PTSD)
Here's your citation in American Psychological Association (APA) format:
Post-Traumatic Stress Disorder (PTSD). (n.d.). In Alleydog.com's online glossary. Retrieved from: https://www.alleydog.com/glossary/definition-cit.php?term=Post-Traumatic+Stress+Disorder+%28PTSD%29