loony toons vs back breaker

loony toons and back breaker both are nouns.

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

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

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

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

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