repression vs defense reaction

repression and defense reaction both are nouns.

Word	Noun	Adjective	Verb	Adverb
repression	Yes	No	No	No
defense reaction	Yes	No	No	No

As nouns, defense reaction is a hypernym of repression; that is, defense reaction is a word with a broader meaning than repression:

repression: (psychiatry) the classical defense mechanism that protects you from impulses or ideas that would cause anxiety by preventing them from becoming conscious
defense reaction: (psychiatry) an unconscious process that tries to reduce the anxiety associated with instinctive desires

Other hypernyms of repression include defence, defence mechanism, defence reaction, defense, defense mechanism.

repression (noun)	defense reaction (noun)
the act of repressing; control by holding down	(psychiatry) an unconscious process that tries to reduce the anxiety associated with instinctive desires
(psychiatry) the classical defense mechanism that protects you from impulses or ideas that would cause anxiety by preventing them from becoming conscious
a state of forcible subjugation