back breaker vs loony toons

back breaker and loony toons both are nouns.

Word	Noun	Adjective	Verb	Adverb
back breaker	Yes	No	No	No
loony toons	Yes	No	No	No

As nouns, back breaker and loony toons are synonyms defined as:

back breaker and loony toons: street name for lysergic acid diethylamide

Other synonyms of back breaker include acid, battery-acid, dose, dot, Elvis, Lucy in the sky with diamonds, pane, superman, window pane, Zen.

back breaker (noun)	loony toons (noun)
street name for lysergic acid diethylamide	street name for lysergic acid diethylamide