防ぼう衛えい機き制せいぼうえいきせいMeanings1noundefense mechanismPsychological term for unconscious strategies that protect the ego from anxiety or unacceptable impulses.フロイトは防ぼう衛えい機き制せいの概がい念ねんを提てい唱しょうした。Freud proposed the concept of defense mechanisms.