back breaker vs Lucy in the sky with diamonds

back breaker and Lucy in the sky with diamonds both are nouns.

Word	Noun	Adjective	Verb	Adverb
back breaker	Yes	No	No	No
Lucy in the sky with diamonds	Yes	No	No	No

As nouns, back breaker and Lucy in the sky with diamonds are synonyms defined as:

back breaker and Lucy in the sky with diamonds: street name for lysergic acid diethylamide

Other synonyms of back breaker include acid, battery-acid, dose, dot, Elvis, loony toons, pane, superman, window pane, Zen.

back breaker (noun)	Lucy in the sky with diamonds (noun)
street name for lysergic acid diethylamide	street name for lysergic acid diethylamide