back breaker vs window pane

back breaker and window pane both are nouns.

Word	Noun	Adjective	Verb	Adverb
back breaker	Yes	No	No	No
window pane	Yes	No	No	No

As nouns, back breaker and window pane are synonyms defined as:

back breaker and window pane: street name for lysergic acid diethylamide

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

back breaker (noun)	window pane (noun)
street name for lysergic acid diethylamide	street name for lysergic acid diethylamide