hand brake vs emergency

hand brake and emergency both are nouns.

Word	Noun	Adjective	Verb	Adverb
hand brake	Yes	No	No	No
emergency	Yes	No	No	No

As nouns, hand brake and emergency are synonyms defined as:

hand brake and emergency: a brake operated by hand; usually operates by mechanical linkage

Other synonyms of hand brake include emergency brake, parking brake.

hand brake (noun)	emergency (noun)
a brake operated by hand; usually operates by mechanical linkage	a brake operated by hand; usually operates by mechanical linkage
	a sudden unforeseen crisis (usually involving danger) that requires immediate action
	a state in which martial law applies