trades union vs brotherhood

trades union and brotherhood both are nouns.

Word	Noun	Adjective	Verb	Adverb
trades union	Yes	No	No	No
brotherhood	Yes	No	No	No

As nouns, trades union and brotherhood are synonyms defined as:

trades union and brotherhood: an organization of employees formed to bargain with the employer

Other synonyms of trades union include labor union, trade union, union.

trades union (noun)	brotherhood (noun)
an organization of employees formed to bargain with the employer	the feeling that men should treat one another like brothers
	people engaged in a particular occupation
	an organization of employees formed to bargain with the employer
	the kinship relation between a male offspring and the siblings