brainish vs tearaway

brainish is not a noun while tearaway is a noun.

Word	Noun	Adjective	Verb	Adverb
brainish	No	Yes	No	No
tearaway	Yes	Yes	No	No

As adjectives, brainish and tearaway are synonyms defined as:

brainish and tearaway: characterized by undue haste and lack of thought or deliberation

Other synonyms of brainish include hotheaded, impetuous, impulsive, madcap.

brainish (noun)	tearaway (noun)
	a reckless and impetuous person

brainish (adjective)	tearaway (adjective)
characterized by undue haste and lack of thought or deliberation	characterized by undue haste and lack of thought or deliberation