Depression vs Great Depression

Depression and Great Depression both are nouns.

Word	Noun	Adjective	Verb	Adverb
Depression	Yes	No	No	No
Great Depression	Yes	No	No	No

As nouns, Depression and Great Depression are synonyms defined as:

Depression and Great Depression: a period during the 1930s when there was a worldwide economic depression and mass unemployment

Depression (noun)	Great Depression (noun)
a period during the 1930s when there was a worldwide economic depression and mass unemployment	the economic crisis beginning with the stock market crash in 1929 and continuing through the 1930s
	a period during the 1930s when there was a worldwide economic depression and mass unemployment